Just do it. And plan to spend a LOT of time doing it as it takes a while to get used to.
+1 on the SpinDoctor (Minoura) cheapo truing stand. You can adjust wheels using brake blocks, but the stand makes things much easier.
Remember when you're moving the rim left, loosen right first. If you're moving the rim right, loosen the left first. Failure to loosen the opposite group of spokes will affect the roundness of the wheel.
Remember that the last step in any repair is to untwist the spokes. Twisted spoke will progressively unwind and throw the wheel back out of true. If multiple spokes unwind, the wheel may come apart.
I personally got into wheel building because I was 270# and riding off road. I was constantly taking my wheels in to get looked at and the LBS was seemed to always be swamped. I wasn't getting the use out of my wheels. I started by truing the wheels and making all the mistakes I listed above. Now I build my own wheels.