Do i need to be logged in on the website mining pool to mine coins? Can i log off the pool mining website and just leave cudaminer running and still mine coins in the mining pool?
No, don't worry. It's just a controlpanel-style thing for keeping you informed; you don't need to stay logged in to that frontend in order to earn your poole shares.
Make sure to keep your actual miner running though: most OSes allow to conveniently put it in the background (so you can log out of your box, too) while running your miners and earning coins.