Americans can only travel directly to Cuba under special circumstances: journalist, humanitarian, government, religious, etc. Due to our partial trade embargo with the country, it is illegal for Americans to spend any money in the country (Yes, it is a stupid rule…but it plays a role in keeping Cuba beautiful and unspoiled.) The best way to travel there is through Canada or Mexico, depending on where you live and how cheap it would be to get to those places. Travel directly from the US is not unheard of, you just have to possess a pretty good reason, including documentation, for going there. Good luck, and make the trip before Castro is gone!

Via Canada, Jamaica or Cancun is always a sneaky option and I hear it is “do-able”