CuriousButterfly, just keep practicing! I took a class that taught me how to shoot in Manual mode, that is all I shoot in for the most part now. Other than when you need to be quick. I used to shoot in A mode before manual, loved that too and I learned a lot in that mode. See about taking a class if you can, definitely worth it!
SBCheezits, the noise is almost non-existant on the Nikon D700. I've cranked that baby up to 6400 to test and it was very crisp without much grain.
HintOfLime, my first dSLR was the D40x. Great first camera and fun to shoot. It is sitting in the closet now. It makes a great backup if I need to go somewhere that will be raining or near water.