Oh...one other thing...

There's nothing wrong with mixing in headphones. A good pair - or one that you "know" well - will get you really close. Don't let anyone tell you it is "wrong" somehow.

It is good to have a pair of studio monitors to finish with, but not an absolute necessity. Keep an eye out for a sale at the major online music retailers for an inexpensive pair of power monitors - no need for an amp (Stupid Deal will have them once in a while). For anyone who will be doing mixing on an on-going basis, it's a good idea... (saves all those trips to the car).