I'm not sure if anyone can list them, at least off the top of their heads. "Conventions" in rails just means the default behavior for a given feature. Most features have sane conventions, and most likely what you were intending to do. For example, in Rails 3, ERB's <%= something %> construct automatically escapes HTML, because 99% of the time that's what you'll want to do.
I suggest just keep learning. With conventions, there's a lot less to remember when you're learning because of these conventions. Conventions just become "the rails way" and if you ever need to do something outside of them, then you look up how to do it.
