I'll throw-in some "seconds" on things already said, here, and follow-up with some other info.
As far as materials sourcing, I tend to go to the following:
I'll definitely concur with other advice given with respect to double-butted spokes: always use them. Contrary to what may seem intuitive, they are not only lighter, but also stronger than straight gauge spokes. The only reason to use straight gauge spokes is that they are slightly cheaper -- which is not a good reason since the savings is miniscule compared to the total cost of a wheel.
Back in the day I was a huge fan of 36 spokes, but with modern materials 32 is absolutely fine for almost anything except heavily loaded touring on rugged terrain.
Though it's a significant expense, my opinion is that you will make your life easier by investing in a nice, self-centering truing stand. They can often be had on ebay, but be careful about what you're getting.
Another relatively expensive-ish item that I would recommend to a beginning builder is a tensiometer. If you're not checking actual tension while building and truing, it's surprisingly easy to get things out of whack pretty quickly. A tensiometer keeps everything honest and -- at least in my opinion -- is crucial with the deep-dishing required for many modern rear wheels. Hitting the tension recommended by the rim manufacturer is important.
Clean and prep the threads appropriately. That means cleaning in a non-polar and polar solvent, and then using an anti-friction, adhering prep such as that sold by Wheelfanatyk. Don't put oils on the threads, or on the spoke nipples, contrary to what you might hear elsewhere.
But DO put a highly viscous oil between the spoke nipple and the rim. This is a very important step that many people miss. Wheelfanatyk also sells a great build oil that I use and highly recommend.
I've used many different spokes for at least 100 builds, and I've landed on Sapim as my favorites. I use them, now, exclusively.
Get a copy of Jobst Brandt's book. No other single source of information has better, more solidly-grounded advice on just about every aspect of spoked bicycle wheels.
I live in Portland, but my brother lives in SF, and I've spent some time in the SF Bike Kitchen. IMO, not the most conducive environment for concentrating on something like a first wheel build. The work areas, also, are a bit small for wheel building. You need to be able to focus and spread out, so I would highly recommend doing it in your own home/place if you can. At the very least, lace your wheels at home and then take them to a co-op shop for the tensioning and truing.
Above all: go in with confidence, knowing that it ain't rocket science. You can 100% build a pro-quality wheel just by following some key pieces of advice and being methodical about it.
Maybe even MORE above all: don't take my advice on anything without looking into the details yourself. It's one of those things where you can ask 10 wheel builders their opinion on any given topic, and you'll get 14 answers. Everyone's got their take to add, and you'll do well to approach it from your own angle and gather your own information. Personally, I can't stand to just do something a certain way just because someone in authority said so. I have to know why I'm doing it that way. Learn WHY before actually doing, and the pieces of the puzzle will all start to fit together for you.