Books in the HS Library:

William Barrett Travis B/TRA

Sam Houston B/HOU

James Bowie B/BOW

Lorenzo de Zavala B/ZAV

Juan Seguin B/SEG

James Fannin B/FAN

David Crockett B/CRO

General José Urrea (online: TSHA)
Antonio de Lopez de Santa Anna (online TSHA)
David G. Burnett (online TSHA)

Online Resources:

The Battle of the Alamo
http://www.thealamo.org/battle.html

The Defenders
http://www.thealamo.org/defend.html

Texas State Historical Association
[A Digital Gateway to Texas History at the University of Texas at Austin]
http://www.tsha.utexas.edu/search/index.html

Browsing the database of names:
http://www.tshaonline.org/handbook/online/browse/index.html

David G. Burnett
http://www.tshaonline.org/handbook/online/articles/BB/fbu46.html

Santa Anna
http://www.tshaonline.org/handbook/online/articles/SS/fsa29.html

General José Urrea
http://www.tshaonline.org/handbook/online/articles/UU/fur2.html

Another interesting site:
http://www.earlytexashistory.com/Tx1836/