This is such a good thread!
If you want help on garlic, I feel like I could help you with what I've learned. I over winter it and there are almost no weeds.
I don't know anything about overwintering onions, shallots, leeks?? Can they be overwintered? Garlic and onions are in the same family, so can they be treated the same?
I put in a flat sheet composting garden also known as lasagna garden last year for herbs, tomatoes, peppers, and lettuces, in just ONE year, and it was prolific, it was amazing. (one of 4 gardens now) I am sure I'll start one of the other gardens into a flat sheet composting garden, so I don't have to have it tilled.
Mulching is KEY. Start collecting biodegradable materials now, (and always) and the weeds will be so much less of a problem.
I agree with those that plant garden plots with some of the more unique and expensive items instead of the more common items because, for me, I can harvest those unique and expensive items which I wouldn't afford at the grocery store.
Examples: Tomatillas--green salsa, eggplant--meatless deliciousness, rutabagas--in pasties, lettuces, herbs. Think of what you want to buy but they are so expensive you don't buy them. Grape leaves, free on the roadside, can them, $6.99 for 36 of them when you buy them.
Now is a good time (at least here in the midwest) to start your plants, order your seeds, so when it is warm you can begin to plant. Kathleen, I am very happy for you, and I hope your garden plot turns out wonderful!