Very nice for your first time. I tried photoshop back in 2003 and had absolutely no idea what I was doing at all. LoL so you're doing an awesome job.

My best piece of advice is to browse CS4 tutorial sites that walk you through step by step. It helped me find out the best what layers or effects would make images the way I wanted them to come out. At first I made things from scratch which included abstract art. Now I find it a very helpful tool for photography

Best of luck and keep up the good work