A new book just released, short, only 236 pages, but written in an "easy to understand style", has short definitions / explanations of many or most of the terminology in the TEXT MINING / TEXT ANALYTICS field. NAMED ENTITY RECOGNITION is contained therein, on page 33:
FUNDAMENTALS OF PREDICTIVE TEXT MINING by Weiss, Indurkhya, and Zhang. SPRINGER, June, 2010: ISBN: 978-1-84996-225-4; it is available on Amazon.com as of this week.
I got my copy last Friday evening, read it over the weekend, and although short and brief in its descriptions, it is comprehensive and a good introduction giving clear, concise definitions and discussions of key components in this field.