Machkas advice if you KNOW you are goin to do this long term. It will be tons more enjoyable in the long run. It will pay off bigtime, it will save you tons of hedaches and time.
jtarver's advice if you are going to do this at least part time, dont have much money and need to make every dollar count, and NEED to get rolling NOW.
The LBS route if you NEED to get going NOW, have money, are only a recreational bicycle driver, and are not sure if you are going to be cycling on a regular basis, IF AT ALL. Did I mention that you need to have money? As in a good amount?
Good Luck! Show us your bike when you get it.