From what I've see and heard, the pronunciations seem ok to me. I'm trying to teach myself some Japanese through tapes, but I've only gotten through lesson 3. ^^;;;
Sites? Um...oh! There's this one site that's like a RPG, but you learn Romaji on it while you play. I haven't tried it myself, however, so I can't vouch for it's effectiveness. Here it is if you'd like.
Gambatte ne! ^_^
*edit* ....Hirigana and Katakana...I would either buy a book or flashcards and try learnign them that way. Unfortunately, I don't know any sites for those, sorry.