At this moment we haven't got an standard process to import Openbravo to Eclipse but we can tell you some steps to begin to work with Openbravo in Eclipse.
First, after creating a new Project (we recommend you create a Tomcat project), you must import all needed libraries.
Then you will need to import in the project "Build Path": src, srcAD and dist/javasqlc folders in order to allow automatic building of the project.
Also i recommend you create some ant task to let you compile the project.