2Tiggies, have fun learning how to use your D90. Don't be scared to experiment, that's how you learn. Like Mike said, we're both pretty new to this too. I still delete plenty of photos, alot of them due to compositions I don't like. I've had a T2i, D5100, and now my Nex 7. All of them were great cameras, I just love the size of the mirrorless bodies and the fact that I can use ANY lens via an adapter.
Mike, do you find that some of your focus points just aren't accurate. I had to delete a couple of shots due to OOF. Some of them were really good shots. I find the center point is always right on but I have trouble with the outer corner points. The camera locks focus but it sometimes front focuses on those points.