You can absolutely re-use hubs. You really, really shouldn't re-use spokes and nipples--it'll result in a wheel you have to true constantly, and risk breaking.

Really, building wheels is NOT even close to as hard as people will have you believe--and there's only one way to learn. You can get a cheap truing stand from Performance or somewhere for less than the price of new hubs/having a shop build it. I'd say, try it yourself, and take it to your LBS to have them look over your first try--if they're cool, there's a good chance it'll cost you a 6-pack.

Oh, and sheldon's site has info on how to put your lacing pattern together.