During the actual development, the Zope Foundation students are required to check in their code in svn.zope.org. This means they are required to obtain commit access. This is a repository the mentors already have access to, and for the students it is a good idea to have write access to svn.zope.org in any case. Your mentor can help get you write access if you don't have it already. See also the links below.
If after the project you want to take your project further and you do not want to use svn.zope.org anymore for some reason, this is open to you, even though we encourage all students to continue contributing there. During the project we should see your work being done in svn.zope.org, however.
In the end, Google requires that all the code should also be submitted to code.google.com and be hosted by them. This we see as a formal final delivery requirement, and not as the main working environment or where we intend to maintain the code in the future.
Guide to obtaining committer access:
http://www.zope.org/DevHome/Subversion/ImpatientPeoplesGuideToRequestingCommitPrivileges
Uploading your SSH key for commit access: