I would recommend gitting the Sierra manual, I think you would use it most of the time, and when a book doesn't mention the exact bullet weight your trying to load with, look at the closest bullet both heaver and lighter, and start between them, and near the bottom of the recommended charge, now you can safely work you way up.
Most guys loading for accuracy will use a bushing type neck sizer, but since you will need a full length (F.L.) sizing die anyway, you might as well start there, and take a good look at Forester or Redding die sets, and you cant go wrong.
There's lots of good info posted above already, so read and heed, and think safety.
FYI:
You can find a barrels twist in 5 min, by using your cleaning rod, a jag, patch and a bit of masking tape.
Start the rod in the chambers bore 2 or 3", then mark the rod with tape at a spot on the action, and put a small flag of masking tape sticking out one side of the rod back by the handle. Now insert the rod until the flag makes one complete rotation, then mark the rod again at the same place by the action. Now remove the rod and measure between the two marks. And you will have the twist, as 1 rotation in ? inches, (or 1 in 9" in your 223)
Mike.