[Newbie] Scaffolding and documentation about scripts

Dear all,

I apologize if the question is silly but I cannot find any hint, so I
am posting here.

Trying to follow some tutorials about RoR 2.0, I see that when you
scaffold you can generate model elements by specifying their
attributes:

generate scaffold post title:string body:text created_at:datetime

The question is, what are the allowed attribute types? Is there a link
to a page documenting this and, in general, the "generate" system?

I've found plenty of tutorials of speedy coding, blogs in 30 seconds,
etc. but they all fails to explains the details.
Good tutorials are for RoR 1.x and don't work with 2.0. Being a newbie
I cannot understand the differences.

Thank you for your help.
LT