Personally, if they are anything alot bigger than a door ding, I wouldn't try it myself. I did once and did more damage than good as I created more divits and waves around the effected area. I ended up having a paintless dent removal "specialist" fix mine. The price was 1/4 of what a bodyshop would have charged.
Try visiting your local car lots (new car sales) and see who they use for their paintless dent removal. The guy I used is the best in town and I later found out he does allmost EVERY dealership in town. There was a hood on a Dodge Ram that was closed on top of a 4x4 piece of wood (the guy set it there then forgot about it before slamming the hood down) he came in and in less than 1/2 an hour the crease was removed and the guy was on his way, the hood looked like new.