Anything for the near-absolute beginner? I've removed the 180-degree angle dirt trap under my sink and cleaned a pipe with a motorized snake, but that's about it. Any book recommendations would be greatly appreciated. Any YouTube videos or usernames would be awesome too.
Home Depot and Lowe's both sell pretty well illustrated, basic books on Plumbing. I have one, "Plumbing 1-2-3" which is from one of those two (can't remember off hand which but I think it's HD) which covers all the basics, has clear pictures, easy to follow directions, and makes you think, 'Oh heck yeah that's obvious...'
As for videos - there's always the DIY network Plumbing section.
You could try the Home Improvement Stack Exchange site, I've heard there are a few guys there that are fairly good at answering most plumbing questions. You can try searching the site in the
Plumbing tag, for questions others have asked about plumbing. Simply enter [plumbing], followed by your query in the search box.
You could also head over to the Meta site and request some plumbing how-to's be added to the blog, I'm sure there are some folks in the community that could write up some good articles.
I second the books put out by Home Depot and Lowes: they have nice pictures and step-by-step instructions.
BUT, I think that they need to be supplemented by practice, before you try to do the real thing. For example: sweating a pipe is easy after about the 3rd try -- if you're doing it in your workshop. If your first time is while you're upside-down under the sink, you'll risk setting the house on fire. And you'll always worry that the joint will burst in the middle of the night.
In addition to the how-to books, I'd suggest looking for a book that covers basic design skills and code requirements -- things like properly sloping and venting a drain. I can't recommend any, but would expect that your local library would have several that you can browse (or get via inter-library loan). This is basic knowledge, and should be the same in any book.