I used to do that, now that I have disc brakes and wheels and with the arch of the suspension fork in the way I said screw it. I didn't want some cheesy truing stand either. This gauge bolts onto the dropout with wheel in place.

For my wheelbuild I followed my Zinn mtb repair book to lace the wheels for front disc brake. There's actually a certain way to orient the heads of spokes for optimum strength. I also followed Mike T's Tech Info page for tensioning and helpful tips. You really only need a spoke wrench, screwdriver and some inside calipers. I tried vernier calipers I had but they didn't work so great.

Mike's page was really inspirational for me realizing that I could do this, and likely build a better quality wheel than a shop will because I can put unlimited time into making it as perfect as possible.