Most of the documentation you need to make web sites can be found for free on the Web itself. Most books that are available are already out of date by the time they're published, and don't cover all of the things you'll want to know. If you'd like to have a handy printed reference, however, and have a bunch of extra money to spend the following is a list of pretty good looking books.

These books should all be available at the NYU Computer Store or the Barnes and Noble at Astor Place.

General Reference
HTML: The Definitive Guide, Musciano and Kennedy, O'Reilly, 1998. ISBN 1-56592-492-4. $34.95
Excellent general HTML reference.

creative html design, A Hands-On HTML 4.0 Web Design Tutorial, Lynda Weinman and William Weinman, New Riders, 1998. ISBN 1-56205-704-9. $39.95
Excellent content, not enough color, too expensive.

HTML 4 for the WWW, Elizabeth Castro, Peachpit Press, 1997. ISBN 0-201-69696-7. $17.95
Looks good, cheap.

Programming
Dynamic HTML: The Definitive Reference, Danny Goodman, O'Reilly, 1998. ISBN 1-56592-494-0. $39.99.
More a reference than a tutorial.

Learning Perl, Randal Schwartz and Tom Christiansen, O'Reilly, 1997. ISBN 1-56592-284-0. $29.95.
Clear explanations with exercises.

Graphic Design for websites
HTML Artistry, Ibañez and Zee, New Riders, 1998. ISBN 1-56830-454-4. $40
Beautifully produced book.