Originally Posted by
exile
There is nothing wrong with learning how to do your own wrenching. There are plenty of websites (ParkTools, Sheldon Browns, etc.) that can help. You can also post a question on the Mechanics forum or do a search on wheel truing. Plus there are a number of books available at your local bookstore or library.
If you are unsure of what you are doing, then do some research first. And yes, (over or under) tightening all your spokes can get your wheel out of true.
I haven't searched on spokes in particular, but for all the maintenance and minor repairs I've done on my bike I've found a Youtube video which showed exactly how to do it.