[arielm]

Having only been tangentially involved in open sourcing one project (pixelwave.org) I probably can't give you everything, but I do have a few nuggets that might help:

1. Documentation: a very important part of any project is its documentation. A detailed getting started guide, installation/setup instructions, and api documentation are what gets developers interested. If they don't exist, or aren't good enough, the project wouldn't gain any traction.

2. Licensing - there are many types of open source licenses and it's important that you select the right one. Some require attribution and some don't. This is one area I leave up to the experts, but know is important.