The MVP program is a little unusual. Members are rewarded for what they've already done, and get all the benefits for a membership year even if they do nothing further. Of course, most of us just keep right on doing what we're doing and get awarded for multiple years. Do we do it for the benefits? Probably not. Most of us like doing community "stuff" whether that's speaking, writing, forums, blogging, or whatnot. But the benefits matter - they actually enable us to do the community stuff. We get extra information in the form of access to betas or conversations with product groups. We get access to each other, a treasure trove of information. And we get recognition, which can open doors for speaker selection folks, article selection folks, and so on. I also know as someone who regularly hires developers that "Microsoft MVP" on a resume makes a huge difference for me.
Now my MVP lead, Sasha, has written a pair of articles that summarizes many important things about the program. Part 1
calls us super heroes and Oscar winners (blush) and has some useful links. Part 2
goes into the benefits a bit.
Of course many people want to know how to become an MVP. It's a bit like how to get to Carnegie Hall
... practise practise practise. Do the community stuff every chance you get, throw yourself into sharing your knowledge, and when you've been doing it for a while and you know an MVP or two, ask one of them if you think you're at that level yet. If they say yes, ask if they're willing to nominate you. If you think you're really active in the community, but not a single MVP knows you and knows what you've been up to, you haven't been active enough yet. People who don't actively share their knowledge often underestimate what "active" means.
Even if you're not nominated or awarded, I am confident that the community work you do will be its own reward. Approach it like that rather than to earn an award, and you're sure to be happy.