The Zope 3 Base project intends to make it easy for you to add your Zope 3 related project to the base, but we do have some guidelines, just so we have an idea of what is going on in the base:
Subscribe to the z3@codespeak.net mailing list if you haven't already, here:
Send a short mail describing the project, including proposed project name, goal, background, license info, name in svn, etc.
Give it a bit to get responses. If there are positive responses in general, go ahead and check it in. If not, you could try bugging us on irc, on #z3-base on freenode.net.
Of course if there is debate, don't check anything in yet until the situation is clear.
To be able to check something in, you need checkin rights. To obtain those, you need to ask on the list too, or chat with us on IRC.