I think the text book Japanese language is somekind of 'high' Japanese. It is grammatically correct and is also taught in Japanese schools.
If you use some language help to hear the spoken language, they can use Japanse people from all over Japan, but they will suppress there dialect as much as possible so it will sound as 'high' Japanse.
If you are a Japanese anime fan though, all bets are off.
They can use all kinds of dialect and make even fun of it.
Most of it will be meaningless for us がいじん but still it will give you an idea of what kind of dialects they use.
If you use the language you learn from the books you will be understood, although I bet you will have one hell of an accent
