Test releases are for developers and testers only, see the last fedora news summary
on what a tester is supposed to do. If you're not a developer nor a tester, use a stable Core release.
Let me say this once more: Fedora Core test releases are development releases of which the only purpose is to improve Fedora Core before a new release.
If you want to help test, join the test mailing list and the devel list is a good idea as well. Always use latest stuff from rawhide and use bugzilla.redhat.com for bug rapports, if you don't file a single bug rapport or send a single mail to the testing list you're not supposed to be using a test release.