I used this link after reading it over a few times to fully understand it. The thing that was hard was finding exactly what 0 lash was. I made a thread on corral and some said that 0 lash was when you first feel a hint of resistance on the pushrod. So the first time I did it, I went by that, as soon as I felt resistance I went a 1/2 turn more and locked the nut. Well, after I thought I was finished I started the car up and got what sounded like a major rod knock. It was loud and obviously I did it wrong. I was also told by someone on another thread that they found 0 lash by spinning the pushrod until it could no be spun anymore or just barely spun, then go another 1/2 turn. This is how I did it the 3rd time and it went good. Finally the third time was a charm and I set them right. I was happy cause I did it myself and I learned something. In the link you wll see that they go 1/4 turn, but most everyone will say go 1/2 turn.
http://www.totalengineairflow.com/tech/valvelashing.htm