I havent actualy decided yet. I know ill have to join a pool but with just cpu i was thinking primecoin
I'm not all too familiar with primecoin....
I know that Peercoin is really easy to get started mining.
Just goto ppcoin.d7.lt (D7 mining pool)
Sign up and then goto the QuickStart tab for mining software download. Then run start.bat and you're mining right away.
If anything, this will give you a fell of how well your hardware is suited for mining.
I hope this is at least a bit helpful. Good luck!