You set the cam on the lowest part of the lobe, then adjust the pushrod to zero lash, then usually go 21-27 flats, or about 2.5-3.5 turns on the pushrod adjuster, depending on what lifters your using and what threads your pushrods have.
The lifter will start to compress but it'll stop due to the oil inside, and start compressing the valve spring. Let it sit for 15 minutes, or until you can turn the pushrod with your fingers, before moving turning the engine over, or you'll bend a valve. The lifter usually takes about 15 minutes to bleed down, then go on to the next pushrod.
“When the going gets weird, the weird turn professional....” ~ Hunter S. Thompson~
R.I.P. Rubberdown. 1971-2012