The first step is to ensure that you have permission from your employer to contribute to Ubiquity XForms. Details on how to do this, and the form that needs completing are available in Contributing Code to Ubiquity XForms over on the ubiquity-xforms-eng Google Group.

Once you have permission to contribute, you should then look at the CodingStyle.

Afterward, please read CodingUsingSvn and TestingGuidelines. They contain a detailed description of the development process and the thinking behind it, SVN command-line instructions that correspond to the various steps, and guidance on how to test your code.

Finally, here are some additional notes on the mechanics of code contribution using Eclipse with Subversion, at CodingWithEclipse.