For a general introduction to LaTeX, including the new features of LaTeX2e, you should read LaTeX: A Document Preparation System, Leslie Lamport, Addison Wesley, 2nd ed, 1994.
A more detailed description of the LaTeX font selection scheme is to be found in The LaTeX Companion, Goossens, Mittelbach and Samarin, Addison Wesley, 1994.
The LaTeX font selection scheme is based on TeX, which is described by its developer in The TeXbook, Donald E. Knuth, Addison Wesley, 1986, revised in 1991 to include the features of TeX 3.
Sebastian Rahtz's psnfss software contains the software for using a
large number of Type 1 fonts (including the Adobe Laser Writer 35 and
the Monotype CD-ROM fonts) in LaTeX. It should be available from the
same source as your copy of LaTeX.
The psnfss software uses fonts generated by Alan Jeffrey's
fontinst software. This can convert fonts from Adobe Font Metric
format into a format readable by LaTeX, including the generation of
the .fd files described in Section 4. The
fontinst software should be available from the same source as your
copy of LaTeX.
Whenever practical, LaTeX uses the font naming scheme called `fontname'; this was described in Filenames for fonts, TUGboat 11(4), 1990 and is actively maintained by Karl Berry.
The class-writer's guide LaTeX2e for Class and Package Writers describes
the new LaTeX features for writers of document classes and packages
and is kept in clsguide.tex. Configuring
LaTeX is covered by the guide Configuration options for LaTeX2e in
cfgguide.tex whilst the philosophy behind our policy on
modifying LaTeX is described in Modifying LaTeX in
modguide.tex.
We are gradually turning the source code for LaTeX into a LaTeX
document LaTeX: the program. This document includes an index of
LaTeX commands and can be typeset from source2e.tex.
For more information about TeX and LaTeX, please contact your local TeX Users Group, or the international TeX Users Group. Here are some useful addresses.
TeX Users Group, P.O. Box 1239, Three Rivers, CA 93271-1239, USA
Fax: +1 209 561 4584 Email: tug@mail.tug.orgUK TUG, 1 Eymore Close, Selly Oak, Birmingham B29 4LB, UK
Fax: +44 121 476 2159 Email: uktug-enquiries@tex.ac.uk