Before you do any shopping online you may want to read this information.
Safe Shopping is an informational  site created by the American Bar Association, to help you order safely online.
There are so many sites devoted to shopping that it is impossible to list them individually. There are, however, several good general sites which will point you in the right direction.  
The All-Internet Shopping Directory - this is a useful site
Secure Online Shopping Malls Search Engine - didn't I tell you there was a search engine for everything!
Yahoo shopping - you can search here for a shopping site by product.
Ninemsn  - australia, hundreds of links...
Britannica - Britannica's guide to over 2000 merchants on the web!
Waterstones - we have used them and found them very good.
Amazon -  not just books but cds toys all sorts of stuff