Go to electroids.com or adafruit.com and buy a kit for a USB-based iPod charger, and get a USB recharge cable for your phone. That will take care of regulation and let you get just the parts you need rather than having to buy five or ten or twenty of something you need one or two of.

PM us if you get stuck, a lot of us know the electronics, but these are actually a pretty easy kits. You don't have to know what the individual parts do, just which way they go. Don't solder your fingers. Use good solder. Tin your iron, don't count on it being done right at the factory, and remember to get a solder sucker.