[texhax] Book(s) to learn LaTeX

[Karl Berry]

    a good book or two that can give me good practical
    knowledge of how things work.

For that specific purpose, I can suggest Learning LaTeX.  It is a short,
example-based book.
http://www.ec-securehost.com/SIAM/ot55.html
(Here's a review: http://tug.org/books/reviews/tb107reviews-learnltx.html)

For a longer book, many people like A Guide to LaTeX2e, by Kopka & Daly.

The LaTeX Companion, already mentioned, is longer still, 
with many more details.

For links to these and a lot more books, both printed and online, see
http://tug.org/begin.html#doc and its references.

Best,
Karl