I really don't like cutting images using the lasso tool or magic wand alone. What I'll do is use those to cut away the background around the body and then I'll zoom right in and use the eraser brush to do the rest, otherwise I just never get a smooth result. It's a pain doing it by hand but I think it's best.
I get all of my brushes and backgrounds from deviantart.com, you can put the most vague description in the search box and you always seem to get a result. Just make sure that whatever brushes you download have been made in ps7 or a lower version otherwise they won't work. This being said, it's incredibly easy to download an image pack and define your own brushes in your version of photoshop. Just open the image and go edit> define brush and it'll be in your brushes pallette.
I'm awful at explaining but I hope that helps. I don't think your graphics are that bad at all, you'll quickly do more complicated things once you've been using photoshop a while