Re: solder iron wattage
Buy one at an electronics specialty shop, and ask them which one they suggest. Do not get one at Radio Shack or a home improvement store, as those shops, especially Radio Shack, are for average Joes who don't know what they're paying for. The average Radio Shack soldering iron will be equivalent to a dull nail on a heater, rather than a useful soldering iron. You might be able to get a better one there, but it'll be overpriced, and you might as well buy a much better one at Stanley Supply or something. You'll probably only buy it once, so buy a good one.
For wattage, 15-30W is good, so you don't burn the board, but can easily melt the solder.