Hi Andy,
Well now, there is a loaded question. You can load yourself down with darn near every bit of photographic gear you can find and it won't change your pictures one bit. (Trust me, I happen to have learned this the hard way.) The best thing you can do is keep taking more and more pictures until you start to know your camera as well as you know your hand. It has taken me 5 years to even begin to like some of my own shots. What it comes down to is keep shooting. Learn to compose your shots, play with your settings, and practice, practice, practice.
Oh, in addition to digitalcameraworld.com, I highly suggest reading
http://digital-photography-school.com/. Every day is a new topic and most are little more than a page or two long, however they are all wonderfully helpful.
Good luck and have fun!
Frank