It's difficult to think of a quick reference broader and more useful than Glover's Pocket Ref. I don't have the Desk Ref
http://www.amazon.com/Desk-Hard-Cover-Th...1282&sr=8-1, but I just added it to my Amazon Wish List.
Doug's pocket survival instructions included in the PSP and PSP+ are in my opinion the gold standard for guides of this type:
http://www.dougritter.com/psp_survival_instructions_0206.pdf and
http://www.dougritter.com/PSP+%20Instructions.pdf .
I'm a big fan of the SAS Survival Handbook, and this version is both easy to carry around and inexpensive:
http://www.amazon.com/SAS-Survival-Guide...1297&sr=1-2 .
Some of my kits contain knot cards:
http://edcdepot.com/careyandcompanyknotcards.aspx . I'm also a fan of the same company's cloud cards:
http://edcdepot.com/careyandcompanycloudcards.aspx .
American Science & Surplus carries reference cards for fish and game that I've found useful, go to
http://sciplus.com and search their catalog for "deer".
There's a CERT Field Operating Guide that I'm fond of:
http://www.amazon.com/CERT-All-Weather-Field-Operating-Guide/dp/B001CS7M3C .
And finally Rescue Essentials has an Immediate Action Card for first responders that I require all of my CERT teammates to carry:
https://www.rescue-essentials.com/ProductDetails.asp?ProductCode=IAC1 .
I've no affiliation with any companies mentioned here other than as a customer with two exceptions. I'm a mod at the ETS forums so it's not surprising that I'm a fan of Doug's stuff. Also, I'm a CERT member and Team Leader, and the last two references are standard issue for my team (the Immediate Action Card was instituted by me).