if you are looking for Marx Brothers Books, Records and Videos you can find
listings at:
http://members.aol.com/marxbroths/index.htm
Available items can be ordered directly from Amazon.com (they will search for
out-of-print items).
At the moment I am extending the information about the movies and vaudeville
shows. You will also find biographical information and listings of Radio and TV
shows.
Depending on what you would like to read I would recommend the following books:
If you want books which are good to read and entertaining get
- "Groucho, Harpo, Chico and sometimes Zeppo" by Joe Adamson
- "Harpo speaks" by Harpo Marx and Rowland Barber
- Books written by Groucho
If you are more interested in facts get
- "The Marx Brothers Encyclopedia" by Glen Mitchell
- "The Complete Films of The Marx Bros." by Allen Eyles
A good source of information about Groucho's last years is "Raised Eyebrows" by
Steven Stoliar.
"Groucho" by Hector Arce is a great biography and he also wrote "The
Grouchophile" which presents a
lot of photos and other material and "The secret word is Groucho"  about the TV
show "You bet your life" 
(do not confuse the last one with a book of the same title by Groucho's cook
John Barrow, that one is only
for fanatic collectors. It is neither well written nor gives very accurate
information)
Hail Freedonia
Stefan