OP, given your scale and location, you might find Charles Dowding's work on no-till gardening useful? He seems to keep things nice and simple for beginners. :)
The cover crop rotation you're describing will certainly add organic matter to the soil and improve soil structure. However, I know I'm not alone in finding that rye/vetch can be a pain to get rid of (tenacious roots!) without a rototiller! Especially if you're using raised beds on a small scale. In a backyard garden, mulch (ie pre-cut grasses similar to rye!) can be really useful and effective. Mulch is almost prohibitively expensive on a farm-scale, hence the cover crops so often recommended. But in a backyard setting, mulch is a miracle. Do you already have some garden beds set up? Google sheet-mulching or lasagne-gardening; even for established beds this can be really useful to improve the soil.
It will be important for you to find out from local folks what kinds of amendments gardens usually need in your area. For instance, in the PNW, where I am, steady winter rains mean soils do leach out calcium and magnesium, and applying lime each year is important; no matter how much we complete our recycling of nutrients via compost etc in our gardens, we will likely always need an application of lime (or wood ash, as a more likely substitute). Your area might be more alkaline, though?
Animals can be extremely useful to build soil fertility. We ended up with the ever-popular chicken coop. So here's what I do, with great success. I "import" hay, grown locally (probably with fertilizers, but without herbicides) when it's too old for animal feed (so is a cheap, waste product). I use the hay in my chicken coop, and it gets well manured. I then compost it with all of our kitchen scraps and other garden waste, and put it back on the garden. In the fall/winter, I lime my property lightly. When I plant, I do add some organic fertilizer: a simple blend of alfalfa meal, lime, kelp meal, and bone meal. This is a slow-release fertilizer that provides a broad range of nutrients. I haven't done a soil test, and I should; after 5 years, veggies still grow really well, but it's possible I'm providing more nutrients than necessary.
In the fall, as in your climate, we still have a lot growing, which can also make planting cover crops a pain. My tomatoes stay reasonably productive until after a hard frost, which here is in late October/early November, which is really too late to plant rye effectively. So I focus instead on protecting the soil from the winter rains. I generally either mulch with some of the chicken bedding (if it will be 6 months before I harvest anything from that bed), or leave a protective layer of garden waste in the bed. This could be all the tomato vines that are simply cut up and left on the bed, etc. During our hot, dry summers, I buy a bale or two of straw and mulch over dripline to keep the soil moisture in. So in many beds, I simply chop up the plants and leave them on top of the straw. All of this will be broken down very nicely come spring, and then I add compost, a little manure from another farm, and a bit of the fertilizer when planting. Overwintered crops like garlic, and perennials, get a compost layer in early spring as well. So far everything thrives.
Sometimes thinking about your crop rotation AS a cover crop can be useful. So, plant peas (as a nitrogen-builder that also gets you edibles) as your short, early season crop (I plant in late Feb for a harvest in June in a similar climate). Instead of pulling these out in July, just chop them down and leave them as mulch, and then transplant in something like a fall brassica that will grow from July to be harvested through the winter. In the spring, when these have been harvested, add compost and a crop that can be planted or transplanted in April (lettuce, potatoes?). Or you could then plant another nitrogen crop, like beans. Or, in March/April you could plant a quick cover crop like buckwheat, which could be cut down in late June when you're ready to plant some warm season crops like cucumbers, or transplant your tomatoes, or start a fall greens or root veg bed. The problem with intensive gardening (which is extremely productive!) is often that all of our beds are full most of the time, and it's tough to sacrifice the space for just a cover crop. This is climate dependent to some extent, I guess, but you should (as I can) be able to grow a really long fall/winter crop, rather than getting frozen out for a few months.
I wouldn't say I'm at a point of no inputs, and I'm not sure that that's possible. But it is possible to stick to organic (as opposed to inorganic) ways to feed the soil and the plants, keep things simple and not expensive, and to have a thriving homestead garden. Good luck to you!
