IGN has gone the extra mile with their new Marvel Vs Capcom 2 guides.

They've got an actually useful beginner guide, an advanced techniques guide, a guide to individual characters, achievement/trophy tips, and even a "Q&A" section with their own MVC2 fanatic (who actually looks like they know what they're talking about  :)). 

It's helpful for everyone from beginners to people dipping their toes into the deep end of the pool, with descriptions (and video!) of everything from the basics to advanced techniques like unfly, guard breaks, wave-dashing, and the all-important triangle jump. 

Check it all out here.