I think the following website covers the "black art"
http://sheldonbrown.com/wheelbuild.html
You may find it useful to give your hub and rim a full coat of paint, just to get into the nooks and crannies before the spokes get in the way, but then make allowances for the fact that no doubt the paint will get an odd chip on it and will probably need another quick coat of paint. I'd try to loosely assemble the wheel on a piece of carpet just to avoid the paint chips. My wheelbuilder told me to adjust the spokes in groups of 4 to correct runout (slacken 4 on the low side and tighten the 4 opposites on the high side) I did my own on my Harley WLA but they have a good section on the wheel build in the manual, most of the British manuals dont have this section, but I soon realised that my wheelbuilder only charged £15 per wheel plus parts so I never bothered again! It appears that £40 is now the normal price per wheel for the labour.
A good source of information is The Vintage Motorcyclists Workshop by Radco. An electronic version was available from the AJS/Matchless website. (I don't know how legal this is though.)
The specilaist may ask you for the offset you require. There are various posts dealing with the offset on this forum, but I am not sure if there is concensus on what the offset should be?
Attached are some lacing patterns for front and rear.