Recommend a book....

I would suggest beginning with a more over view book.
Absolute Beginner's Guide to Computer Basics by Michael Miller
has a some good info those just joining this hobby.
amazon.com has a very good selection of introductory books. Your local book store might too.

Rosch's Hardware Bible. It's got a lot of technical details, but it's written for everyman (ie: overview-esque style.)

I love Dummies books to death, but they're no good for operating systems. I'd suggest a book like the Missing Manual. I got one for Mac, and it was great. They also make one for XP.

I'm mostly self-taught, but I have read a lot of books. Find a series you like and go from there. For example, there's a Bible series that's pretty good (the Adobe InDesign Bible, etc.)

There's a great Dummies book on building PCs as well. I got it awhile, lent it to my friend, and haven't seen it since. It gives a really good overview of building a PC as well as how to actually do it and what parts you need (including ranges, from budget to blow-out).

If you want to become a serious power user, take some time to learn the keyboard shortcuts for Windows and for each of the main programs you use. You'll be way faster when working on a PC that way.

Mostly, just screw around with computers. Surf the web, get some basic parts from Ebay and play with them. For me, learning networking was really a hands-on experience rather than a book-reading experience. You have to learn the little nuances of actually setting one up by doing it and getting a feel for it. It's like when you're learning to fly airplanes, you can only read so much before you have to get an actually feel for the plane itself to really understand how it works and how to use it.

Computer software and hardware is pretty easy to learn for anyone, but networking is whole other game. On a home level it is pretty basic but in a enterprise level the sky is the limit.

I use all kinds of forums such as this, and that is way better than any books. Also read review on type of hardware you are interested in, often times you can learn alot more than ya think.