Great question! I will be happy to kick it off with a few links to consider:
in-retrospect-113284.html - great overview by Rhyme about the bschool rat race
I would say start thinking about what you will need for a great MBA application:
1. Letters of recommendation - make sure your boss loves you and wants the best for you (this may or may not be possible)
2. Extra curricular experience and activities - get involved with what you like - be active, more personable, and involved in SOMETHING
3. Be good at what you do - whatever that is
4. Be interesting. Don't be a boring computer gamer who is terrible at games. Instead consider trying new hobbies, improving your speaking skills with Toast Masters, overcoming your weaknesses, and doing bold things
5. Take risks at work so you can write an essay about successes and failures
6. Review some of the topics for essays for the top schools you are considering and think about what examples you could bring up (save those questions somewhere and review them every month or so and see if any of the projects you are working on or offered can help you)
7. Offers others help
8. Learn to say no politely
9. Read some books
mba-books-good-books-to-read-prior-to-mba-74557.html - a bit dated but I feel Ayn Rand's Fountainhead is a must still