Some very fine tutorials have been written, over the years. Michael Doob's splendid 'Gentle Introduction' to Plain TeX (available on CTAN) has been stable for a very long time. Another contender in the same game is from one D. R. Wilkins, available on the web at http://www.ntg.nl/doc/wilkins/pllong.pdf
More dynamic is Tobias Oetiker's '(Not so) Short Introduction to LaTeX2e', which is regularly updated, as people suggest better ways of explaining things, etc. The introduction is available on CTAN, together with versions in the some of the many languages it has been translated into.
Harvey Greenberg's 'Simplified Introduction to LaTeX' was written for a lecture course, and is also available on CTAN (in PostScript only, unfortunately).
Peter Flynn's "Beginner's LaTeX" (which also started as course material) is a pleasing read. A complete copy may be found on CTAN, but it may also be browsed over the web (http://www.tex.ac.uk/tex-archive/info/beginlatex/html/).
TUG India is developing a series of online LaTeX tutorials which can be strongly recommended: select single chapters at a time from http://www.tug.org.in/tutorials.html~- the set comprises two parts, "Text" and "Graphics", so far.
Another item, not quite FAQ, not quite tutorial, is Herbert Voss's excellent LaTeX tips and tricks.
An interesting (and practical) tutorial about what not to do is l2tabu, or "A list of sins of LaTeX2e users" by Mark Trettin, translated into English by Jürgen Fenn. The tutorial is available from CTAN as a PDF file (though the source is also available).
The AMS publishes a "Short Math Guide for LaTeX", which is available (in several formats) via http://www.ams.org/tex/short-math-guide.html
Herbert Voss is developing a parallel document, that is also very useful; it's part of his "tips and tricks" mentioned above: http://www.perce.de/LaTeX/math/Mathmode-TeX.pdf
Keith Reckdahl's "Using Imported Graphics in LaTeX2e" is an excellent introduction to graphics use, though it's slightly dated in not discussing anything other than the dvips route. Available on CTAN, but again without sources.
An invaluable step-by-step setup guide for establishing a "work flow" through your (La)TeX system, so that output appears at the correct size and position on standard-sized paper, and that the print quality is satisfactory, is Mike Shell's testflow. The tutorial consists of a large plain text document, and there is a supporting LaTeX file together with correct output, both in PostScript and PDF, for each of A4 and "letter" paper sizes. The complete kit is available on CTAN (distributed with the author's macros for papers submitted for IEEE publications).
For Plain TeX commands a rather nice quick reference booklet, by John W. Shipman, is available.
Special-purpose tutorials are always useful, and an example is set by Haruhiko Okumura's page on http://www.tac.dk/cgi-bin/info2www?(latex)
More ambitiously, some departments have enthusiastic documenters who make public record of their (La)TeX support. For example, Tim Love (of Cambridge University Engineering Department) maintains his deparment's pages at http://www-h.eng.cam.ac.uk/help/tpl/textprocessing/, and Mimi Burbank (of the School of Computer Science & Information Technology at the University of Florida) manages her department's at http://www.csit.fsu.edu/~mimi/tex/~- both sets are fine examples of good practice.
People have long argued for (La)TeX books to be made available on the web, and Victor Eijkhout's excellent "TeX by Topic" (previously published by Addison-Wesley, but long out of print) was offered in this way at Christmas 2001. The book is currently available at http://www.eijkhout.net/tbt/; it's not a beginner's tutorial but it's a fine reference (contributions are invited, and the book is well worth the suggested contribution).
Addison-Wesley have also released the copyright of "TeX for the Impatient" by Paul W. Abrahams, Karl Berry and Kathryn A. Hargreaves, another book whose unavailability many have lamented. The authors have re-released the book under the GNU general documentation licence, and it is available from CTAN.
Norm Walsh's "Making TeX Work" is also available (free) on the Web, at http://makingtexwork.sourceforge.net/mtw/; the sources of the Web page are on CTAN.
The book was an excellent resource in its day, but is now somewhat dated; nevertheless, it still has its uses, and is a welcome addition to the list of on-line resources. A project to update it is believed to be under way.
This question on the Web: http://www.tex.ac.uk/cgi-bin/texfaq2html?label=tutorials