Q: Who is ________(character name)? I've never heard of them before and they got into this game!
A: While most of these characters are the big bad famous villians/heroes, most of you probably have never read a Ms. Marvel Comic or can name every member of the Wrecking Crew. Visit http://www.marvel.com/universe/Main_Page
for a database of characters, teams, and places. Or you can visit a local comic shop and browse through some issues before they kick you out/force you to buy something.
Q: Where do I go/I'm stuck in ______/ I can't find the switch!
A: Gamefaqs/some threads here have multiple guides. Please read/search through them and if you are feeling especially appreciative, send them a thank you e-mail or small donation (if they are taking them).
(mods: not promoting e-commerce, or boosting my own[i have no guides out there], just illustrating that a lot of time and effort goes into all these guides users make.)