Waterford Press has a bunch of pocket guides on subjects from nature and travel to survival.
It's newest release is the Pathfinder Outdoor Survival Guide Series on subjects from Signaling for Rescue to Building a Survival Kit and Surviving in the Wilderness. They've got some pretty good tips.
I've also seen one on field dressing game that will come in handy.
The lightweight and waterproof guides can easily be carried in a daypack or pocket on treks or hunting trips.
The guides retail for $6.95. For details, go HERE
I've also seen some of the guides at Idaho Mountain Touring in Boise.