I think running into STP issues in a home network is a new one to me. I can't think of any home/small office kit that can even do STP out of the box.
As far as decent documentation, there is a ton of information on cisco.com if you dig around a bit. It'll be very Cisco centric but a lot of it applies in general. I don't know of any decent books off the top of my head. The best way for me to learn was hands on by tooling around with various servers/switches. I was learning it to make money off the skills though so you might not be as interested in spending as much time as I did.
At work we do use
http://www.safaribooksonline.com/ when we actually need a reference book. Monthly subscription and you can view 10 full books/month at a time. It has, possibly the full collection of, Cisco press and O'Reilly which should cover just about everything you would ever want to know about networks. Not everyone can read from a PC screen though which is where I struggle with it a bit.