A Removable Storage system provides two classes of media pools: system and application. System media pools include free media pools, unrecognized media pools, and import media pools. Removable Storage creates one free, one unrecognized, and one import media pool for each media type in your Removable Storage system.
For obvious reasons a camera is really nice to bring along. Big plus if it's a digital camera! Other items: a whistle, in case you get lost or need help ; waterproof matches ; some kind of lip balm/blistex ; sunglasses ; extra batteries for that flashlight! gaiters are great if you're hiking in shorts and it's a bushy or wet trail
Backpacks are for carrying stuff that you don't need until you reach your campsite, like cooking gear and tent pegs. Backpacks are not for carrying anything you need as you're walking around, like cameras or lenses. Bag makers sell a lot of expensive packs to a lot of people new to the hobby. Don't fall into this trap.