Win.
If your keyboard has USB cord, use that. If not, like Ghetto said, you can grab a MIDI interface by USB (or Firewire if you can).
Good DAW's are not a good way to put it. It depends how much of what style you want or how you like to work.
Do you like flexible and modular with no guides as to how to organize your stuff? FL Studio is your best bet, because it offers so many different ways of workflow other than the traditional track system in most DAW's. The flipside is it might take a couple years to learn how to organize your own work, but it pays off.
If you wanna get something more simple and linear and easy to record, get Cubase or Pro Tools or something. I've tried both, don't really have a preference (FL to me is infinitely better than both of them ) but get whatever is cheaper.
Or, you can get Reason. No outside plug ins to worry about, you use what you get inside. A nice and cozy little DAW.
What else do you need? Time.
Lots and lots of time. (to practice)