Wow -- that's a lot of information and a lot of variables, so forgive me if my response is pretty general.
1. I would start by mapping the property. Walk it daily, and get a sense for the topography, the slope, the soil, hydrology, moisture, etc. 10 acres is a lot of land, and you will most likely be using only an acre or two (at least initially) to grow your food. Once you've mapped your property, pick the best spot to start your garden and expand outward from there.
2. You describe your property as sloping from west to east, so it will get decent morning sun. Look for a south facing hill with minimal slope for your primary garden and orchard. Being all the way up in Idaho, you will want to maximize your sun exposure and frost-free days. A south-facing slope will warm up sooner in spring and stay warmer later into the fall. But too much slope will make it difficult to work.
3. Start small and just look to have a couple of wins the first year. Better to be successful with something small than to try to bite off more than you can chew. You mention that previous efforts have all been eaten or stomped. Fencing and other forms of protection are probably your first order of business. If you can safely contain (for example) a quarter of an acre, (about 100 feet by 100 feet) that would grow a lot of food.
4. Don't start planting trees until you've got a good sense for how you want the entire property to be laid-out. The permaculture principle here is that you work in order of greatest permanence. That means swales and water-features, roads and other hardscaping, and fencing all go in before you establish trees and non-permanent plants. I wish I had taken a few years to have a better sense of my property before I started dropping trees in the ground.
5. It's never too soon to start building soil. Simple strategies like mulching (wood chips, if you can get them), cover-cropping, building compost piles, and raised beds (so you can focus your soil enhancement in a very tightly focused space) are all ways to jump-start your soil.
Best of luck.