OK. I suppose the best place to start is to read through the Sheldon Brown website on wheel building to understand the basics.
http://sheldonbrown.com/wheelbuild.html
Not claiming to be an expert, just a guy who would rather put my money into buying more fun stuff than paying people to do things I should know how to do.
I personally do not use a dish stick or a spoke tension meter, although I would like to have a tension meter just to see out of curiosity where I'm putting my spoke tensions but so far I'm too cheap to buy one. The fact that wheels were successfully built without them for many decades tells me this is not a critical tool in the tool box. Used rims almost always have some sort of damage and perfectly even spoke tensions are not possible to achieve a true wheel. I have wasted a lot of time on used rims so I now do this simple test to see if it's worth the trouble of building them up. Remove the spokes and hub from the rim. Lay the rim on the flat ground and if it does not lay flat or very close to it, junk it. You will have spoke tensions all over the place and some spokes might be no more that finger tight to achieve a true wheel on a bent rim. That's not going to stand up to use and remain true.
How do I find the rear dish setting?
#1 Finger tighten all the spokes up on my truing stand and eyeball an offset for the rear wheel.
#2 transfer the rear wheel to the bike frame and find the spot on the rim that perfectly centers the rim in the chainstays. Make sure the axle is fully seated all the way back and down in the drop outs, remove the derailleur hanger to do this. Use the axle nuts and washers and tighten them down to simulate the rear hub in the installed position. Good time to tweak your stays and drop outs if things are too tight, loose or crooked.
#3 Find that perfect spot on the rim by spinning it or create one need be by loosening and tightening the spokes using a scale on the stays. Mark it with a marker. Carefully remove the wheel assembly and transfer it back to the truing stand and set your stand up using your mark.
I use this procedure on all my builds and it has not failed to give me perfect wheel dishing on all my bikes.