Great advise from all. I would second what Game Stalker said, "don't get caught up in the bigger is better craze!" That is the #1, best advise a newer shooter can hear! If you have experience with the .300 and that's what you want, that's OK. But there are not that many critters in NA that need killing with a .300+.
Second, I would recommend buying the gun and scope separately! "Package deal" scopes are usually garbage and would be used as a trot-line weight!
Get the best glass that you can reasonably afford, good luck and welcome to the HN board!