These are some potentially useful links.

Rutgers Linguistics
The very finest Linguistics department here at Rutgers, The Exalted State University of the State of New Jersey

ROA
The Rutgers Optimality Archive is a collection of papers, etc. set within (or sometimes arguing against) Optimality Theory. Most of them are about phonology, but not all.

WALS
The World Atlas of Language Structures Online

isizulu.net
An online Zulu dictionary

EBALL
The Electronic Bibliography for African Languages and Linguistics

Khoisan Linguistics
The Khoisan Linguistics page at Cornell had a lot of useful information (NB: the site may have been taken down)

Doke's problem with Zulu clicks
Did you know that Clement M. Doke did an X-ray study of click consonant articulation as early as 1923?