Hypertext Help with LaTeX
LaTeX Reference Books
A Document Preparation System: LaTeX, by Leslie Lamport, ISBN 0-201-52983-1, published jointly by the American Mathematical Society and Addison-Wesley Publishing Company. The 2nd edition, 1994, describes LaTeX2e, the second widely distributed version of LaTeX. The first edition of this book, which appeared in 1985, described LaTeX 2.09.
The standard reference for what goes on inside TeX is The TeXbook by Donald E. Knuth, ISBN 0-201-13448-9, published jointly by the American Mathematical Society and Addison-Wesley.
M. Goossens, F. Mittelbach, and A. Samarin, The LaTeX Companion, published by Addison-Wesley, ISBN 0-201-54199-8 (essential for the serious LaTeX hackers).
L. Botway and C. Biemesderfer, LaTeX Command Summary, published by the TeX Users Group, Providence, RI is a good companion.
A. Diller, LaTeX Line by Line, published by Wiley.
N. Walsh, Making TeX Work, published by O'Reilly & Associates, ISBN 1-56592-051-1.
Other information is available on the Web.
Thanks to Anthony Stone (Cambridge) for suggestions.