Please direct me to a good book on ANSI SQL.  I am already familiar
with Sybase and MS SQL, but I want something that shows the
"standard".  A plus would be if it offered a comparison between the
standard and MS or Sybase.

First some general background- the 3 most common types of SQL are

ANSI SQL - the standards board(ANSI) that tries to standardize between sql
PL-SQL - Oracles Implementation of SQL
Transact (T-SQL) Microsoft and Sybase's version.

Sybase was the basis of Microsoft SQL Server but they have branched significantly.

A couple of good books:

SQL for dummies (my first book) - Allen Taylor 
A beginner guide  that is a good refernce.

SQL Bible by Alex Kriegel 
A good overview of ANSI SQL 

SQL - The Complete Reference -by James Groff 
A good reference guide

Here is the link to standards document online

http://www.contrib.andrew.cmu.edu/~shadow/sql/sql1992.txt

Thank you, both.