There's a plethora of information on these guys because they've been around for a REALLY REALLY REALLY long time (like since Solomon's time). Much of the info on them is unknown because they're so secretive. There are some people who will claim to know said secrets because they were once members of the fraternity.
The first thing you should know, and this is problem the most common misconception, is that Freemasonry is not a religion. Rather, it's a fraternity (brotherhood) of people who believe in a God. It doesn't matter which God so long as they have a committed belief in one (including the Judeo-Christian God, Jehovah). Traditionally, only males were allowed in the fraternity but recently, meaning the last 100 years or so, some lodges have allowed women to join; although, "Grand" lodges may not recognize such institutions as a Freemasonry body. There are a few women who were permitted to join prior to 1723 though.
A Grand Lodge "Orient" basically connects a bunch of Constituent Lodges, which must be warranted or charted by the Grand Lodge, in a particular jurisdiction. Grand Lodges also authorize meetings or work for Local Lodges. In the United States: there is a Grand Lodge for every state. Other countries like England and London have Grand Lodges for the entire country.
Within the lodges themselves, there is also a hierarchy. "The Worshipful Master" is an elected Mason who acts as the President. Senior and Junior Wardens have similar duties as Vice Presidents. Some lodges also elect a Secretary and Treasurer. All lodges also select a Tyler "Tiler". This office is either appointed by the Master or elected, depending on the policy of the lodge. The Tyler guards the lodge room door during meetings. Some lodges may also elect or appoint Deacons, Stewards, and a Chaplain.
Yet another hierarchy is among the individual members in America. There are two rites, the York (The Knights Templar, a famous military Christian order, is a part of the York rite) and the Scottish, of differing degrees but each begins and ends on the same positions. The York rite takes larger steps with fewer degrees while the Scottish rite takes smaller steps with more degrees.
The first three degrees shared by both rites are as such:
1 Entered Apprentice
2 Fellowcraft
3 Master Mason
The third degree is where most masons will stay. If they want to climb up the hierarchy then they have to enter either the York or Scottish rite. The Scottish rite was begun by Scot migrs in France. The York rite is named after York, England (which is where the 1st masonic body begun, according to legend).
The Scottish rite has 30 degrees, each one teaches a moral. To earn the degree, the mason must learn it and demonstrate it in a dramatic ceremony. The 32 is the highest degree a mason can earn. The 33 is awarded by the Supreme Council, the ruling body of a rite. Here are the degrees of the Scottish rite; where the are two name, left is the Northern and the right is the Southern:
4 Secret Master
5 Perfect Master
6 Intimate Secretary
7 Provost and Judge
8 Intendant of the Building
9 Master Elect of Nine / Elu of the Nine
10 Elect of Fifteen / Elu of Fifteen
11 Sublime Master Elected / Elu of the Twelve
12 Grand Master Architect / Master Architect
13 Master of the Nine Arch / Royal Arch of Solomon
14 Grand Elect Mason / Perfect Elu
15 Knights of the East or Sword / Knights of the East
16 Prince of Jerusalem
17 Knights of the East and West
18 Knigt of the Rose Croix of H.R.D.M. / Knight Rose Croix
19 Grand Pontiff / Pontiff
20 Master Ad Vitam / Master of the Symbolic Lodge
21 Patriarch Noachite / Noachite or Prussian Knight
22 Prince of Libanus / Knight of the Royal Axe
23 Chief of the Tabernacle
24 Prince of the Tabernacle
25 Knight of the Brazen Serpent
26 Prince of Mercy
27 Commander of the Temple / Knight Commander of the Temple
28 Knight of the Sun / Knight of the Sun or Prince Adept
29 Knight of St. Andrew / Scottish Knight of St. Andrew
30 Grand Elect Knight K.H. / Knight Kadosh
31 Grand Inspector Inquisitor Commander / Inspector Inquisitor
32 Sublime Prince of the Royal Secret / Master of the Royal Secret
33 Sovereign Grand Inspector General
There are several figures met by the mason through this hierarchy in rite ceremonies. On the 5th degree, King Solomon; 15th and 16th degree, King Cyrus; 17th and 18th degree, acolyte; 20th degree, George Washington; 29th degree, Sultan.
Now for the York rite, they have 10 steps which aren't known by degree but rather by name. Here are the steps of the York rite (along with the equivalent degrees of the Scottish right in parentheses):
Mark Master (5)
Past Master (9)
Most Excellent Master (13)
Royal Arch Mason (17)
Royal Master or Select Master or Supreme Excellent Master (21)
Order of the Red Cross (25)
Order of Knights of Malta (29)
Order of Knights Templar (33)
Figures also meet masons in the York rite for ceremonies, but this time it's on every step. They are, from lowest to highest: temple workman, Past Master (Virtual), Israel tribesman, High Priest of Jews, King Hiram of Tyre, Knight of Malta, and Knight Templar.
There are several allied organizations with freemasonry. Masons get privelages from these organizations. These are the organizations:
Shrine (only 32 masons or Knights Templar can join)
Daughters of the Nile (only a shriner's wife can be a daughter of the nile)
Tall Cedars of Lebanon
Order of the Eastern Star (only women with a mason in the family)
Grotto
Job's Daughters (only girls with a mason in the family)
Rainbow Girls (only girls with a mason in the family)
Order of DeMolay (only boys with a mason in the family)
There are many symbols in Freemasonry but the most important are: the open Bible with the square and compass on it; Solomon's temple; and the G with the all-seeing eye inside. The G stand for "God", "Grand Architect", or "Geometry". Two interesting things that come to mind.... I've seen a picture of Jesus holding a compass drawing a circle which is creating an earth. And I've also heard that there's a triangle which connects Washington DC to Venus.
So you're probably wondering right about now how this all fits in with Christianity since there seems to be heavy prevalence in symbolism. Well, there's a rich history and tradition to it all. "Mason" is actually a word for "builder". This is also a part of tradition which dates back to building of King Solomon's temple in 1000 BCE. In the medieval ages: the first mason lodge was built. The freemasons built huge cathedrals and temples without the use of mortar. Just pure stone and geometrical knowledge only privelaged to the freemasons. It was thought these building were directly connected to the divine. They also used a special ratio known as the golden ratio, about 1.618..., which was also believed to be connect to the divine. The Pythagorean Theorem is also a great treasure to them. Surely you've also heard of "Sacred" Geometry.
More information:
http://www.freemasonry.bcy.ca/symbolism/golden_ratio/golden_ratio.ppt
http://www.freemasons-freemasonry.com/divine_proportion.html
http://www.youtube.com/watch?v=o5DlXFzj0SE
http://www.facebook.com/album.php?aid=90789&id=1519881814&l=dfb51875be (also check out links in captions)
Anyways, there's a plethora of esoteric information with regards to the maths of the masons. There's philosophical, metaphysical, mystical, religious, linguistic, mathematical, geometrical, astronomical, astrological, musical, numerological, trigonemetrical, molecular/chemical, physical, and pythagorean knowledge that I could talk to you about for days on end. I'll mention one thing though which is my favorite thing to tell. The circle is representative of the number 1 or 0 (pythagoreans didn't use zero), god, and infinity. The square is representative of the materialization (crossing dualities). And the triangle, which all shapes break down to, represents a link between the divine and the material world. Perhaps you've seen a square inscribed in a triangle which is also inscribed in a circle? To me this is something truly amazing, perhaps you don't understand it but I find it oh so intuitive. My neurological circuits just fire on and on with information (I might be up all night because you asked this question).
Some videos on Georg Cantor (The God of Infinity):
Philosophy, Physics, Mathematics "Dangerous Knowledge": http://video.google.com/videoplay?docid=-5122859998068380459
The Mystical Philosophy of Georg Cantor: http://www.youtube.com/watch?v=_Ds6XtElf3E
The Infinities In Between (Part 1): http://www.youtube.com/watch?v=WihXin5Oxq8
The Infinities In Between (Part 2): http://www.youtube.com/watch?v=KhgNiqI-bt0
Now if you want to know more about the Freemasons history in general then watch these (the masons all deny conspiracies, but who knows... one of their mottos is "ordo ab chao" order out of chaos):
(Part 1) http://video.google.com/videoplay?docid=-8535789150894959894
(Part 2) http://video.google.com/videoplay?docid=1836483377108563321
And yes, I have watched every single one of these videos. I could also recommend several books and volumes and dvds and websites and generally any information source you can think of because freemasonry is literally tied to nearly everything due to history.
So what do I think about anti-masonry stuff? Well, I've heard that somewhere along the lines a Satanist influenced freemasonry. I forget his name though. Another interesting thought is that the freemasons are connected to international banking, something that the illuminati and zionism share with. The Rothschilds (I think they practice ancient Druidism), the first of the 13 royal bloodlines of the illuminati, first started the banking business. They're said to own over half of the world's wealth. Have you heard of the Reptilian conspiracy? Either you'll laugh at that or you'll take it seriously.
To learn about the Rothschilds:
(Part 1) http://www.youtube.com/watch?v=8F4IGwuKdUQ
(Part 2) http://www.youtube.com/watch?v=q2Yjoi2_5pw
(Part 3) http://www.youtube.com/watch?v=47WM2BhklmM
So yeah, there's tons of esoteric information to geek out on. AntiGrav tech, Vimanas, Dimethyryptamine, Chakras, Meridians, Religion, Flower of Life, Zero-Point Energy, Hutchison, and things of this sort. Sorry about this chaotic format but I don't know how to format it without dumping the contents out onto the text. So... hopefully this is satisfactory. If you ask specific questions then I can keep it to a minimum.