i'm sure if u google around u'll find tons of sites bout learning italian
i learn italian at school, but as progress was too slow for me (i finally wanted to understand the calcio-related-articles on the internet) i found many great sites that helped me learning all the grammar...
i have learned italian for 2 years now and i can talk without any problems to italians (if they don#t speak dialect...)
Yes, I say go to Italy, that is probably the best way. I know numerous people who have done exactly that and will support that conclusion. I think having to use it all the time and being exposed to it all the time really helps you pick it up.
I had 3 semesters of it in college and I would hardly say I know Italian. It's a lot of work.