Snagged this from Cheapassgamer.com, and it still worked today, so by all means go and save yourself ridiculous amounts on guides.
Currently bradygames.com has a holiday sale until 12/31/05 for 25% off 1 or 2 guides or 50% off 3 or more, but there's a nice trick involved.
First off, this requires signing up for a free bradygames account. After doing so, you can peruse their stock to see what you want, but don't add anything to your cart.
At the top of the page is a link to jump to other sites in the Informit Network, select Informit from the menu or just go to informit.com. This site has all the offered Brady Games guides at an increased discount of 15% more than the bradygames site discount. Search for the guides you want and add them on this site, then switch back over to bradygames.com and if you have 3 or more guides, each should be discounted by 65%. NOTE: The discount will still show as 50% on the informit site until you flip back to bradygames, but once it's added to your cart it will stick.
If you take full advantage you can get each guide for about $5 and change, not bad if there's a few guides you've been wanting. Also, the WoW Atlas pack is 12.25 and the SCII 'guide' is under $3 after the discount. Then, of course while checking out there is free UPS ground shipping thrown in.
EDIT: Add'l info about finding guides (C&P'ed from Shrike)
The list that comes from the informit.com site is a slightly smaller list than the one on the bradygames.com site. Ones that didn't come up doing the "all games" on informit.com list were ones like XML2, COD2, and some of the newest guides. However, if you found the guide on the bradygames.com site, and then went to the informit.com website, pasted the URL for the guide from bradygames.com and replaced the bradygames.com portion of the URL with informit.com , the game guide would show up on the informit.com site.
Added to the cart from bradygames.com, you would just get the 50% discount. When sending it across from the informit.com site, you'd still get the 65% discount. So, if you found a guide on bradygames.com that didn't show up on the informit.com site directly, do the little trick above, add it to your cart, and you should be able to get the guide with the 65% discount. Has to be added from informit.com to get the full 65% discount.