Great work especially for your first go. There are thousands of great tutorials for photoshop on the web. If I am trying to do a certain effect I usually google it and find a step by step tutorial on exactly what I am trying to do with relative ease.
Great work for 1st tries. Are you using point to point when tracing round the car. Give freehand a try, it will give you a smoother image then you can feather the selection.
I was messing all day on photoshop yesterday. I have never used it before. I have tried photoimpact but could never figure out how to cut out an object. It was really annoying. Photoimpact had loads of different wizards to do stuff but it was too clever for its own good sometimes.
My first attempt in photoshop.