I agree that truing is the difficult part of building wheels, and lateral truing is easier than radial truing or rim centering (dishing).
I refer to Jobst Brandt's lacing instructions, but Sheldon's are good too.
While tensioning the spokes I concentrate on radial truing and rim centering simultaneously before worrying about lateral truing.
I'm sure I could buy good wheel sets for less money than what I spend building my own, but I like picking out the parts and build my own.

Al