Welcome back to the wonderful world of gardening! :) (I'm in a happy mood because all of my crocus are blooming!) Without going into too much detail, rotating is used mainly for two reasons: to help prevent the build-up of disease and to help avoid depletion of the soil of certain substances. Any basic gardening (vegetable) book will usually go into detail. But essentailly it boils down to moving plants so that you don't grow the same types of plant in a spot year after year. I started listing what shouldn't go where, but really it is easier if you look in a book. Or online. But corn next to lettuce isn't a problem, whereas peppers where your tomatoes were last year might be. Cheers!

I live in east central Mississippi and I have similar challenges. First, do you know your plant families? Brassicas are cabbage, collards, kale, broccoli etc. Nightshades are tomatoes, peppers, eggplants, etc. Curcubits are squash, cucumbers, and melons. Legumes are sweet peas, snap beans, long beans, edamame, crowders, limas, etc. It's the families you must rotate, not the specific plants. I have 9 raised beds in my garden. I use all 9 beds in the summer, but only 3 in the winter. So each summer (April to October), I devote 3 beds each to legumes, curcubits, and nightshades. I plant twice, sometimes 3 times, in my summer growing season in those beds, but I keep the same family in the bed. For instance, I plant snap beans in spring, follow them with crowders or long beans when it gets hot in mid summer and then more snap peas for a late summer/fall crop. I plant tomatoes in spring, then pull them out in July and follow them with peppers that produce until fall. Here's the thing. I don't have room to grow every crop every year, so I make choices. I rejoice in what I have, and next year rejoice in something different. During the winter (November to March), I grow a bed of brassicas, a bed of roots, and a bed of onions. All the others get a cover crop sown in them. I don't need or want three beds of curcubits most years, so I usually plant a bed of cucumbers, a bed of squash, and then a bed of okra or sweet potatoes in those designated beds. I rotate the okra or SPs around from year to year. So...I rotate the three basic families every three years, giving each family three beds each year. Winter is easier, but again, I only plant three beds so they are easy to rotate. I do try to be sure that the brassicas never follow the nightshades to avoid infestations of flea beetles. Confused? It's not that bad as long as you keep excellent records from year to year and discipline yourself to stick with the plan. And, you can always use pots to supplement. I almost always grow eggplants in pots. It saves more space for tomatoes and peppers and honestly, I think the eggplants do as well as or even better in pots. All that being said, I have found that as long as I take truly excellent care of my soil, I can get away with cheating occasionally.

I think if you had some small shelves that are about as tall as the window sill you could grow plenty. If the shelf ended about 10 inches from the sill the plant would be in the sunshine most of the bright part of the day (assuming its planted in a 10 inch tall pot). You would want lights overhead of the plants during the evening when winter days are the shortest. Plenty of plants will survive without the lights but they will barely grow and probably won't bloom and fruit during the shorter days. You could use regular adjustable floor lamps with the bulbs set within a foot of the top of the plants (the closer the better) and either use grow bulbs or fluorescents. Lighting is tricky. People seriously growing under lights use big bulky expensive lamps that won't work well in a home-ey sunroom if you want to also use it as a reading/sitting room. I would at least start out with something simple and expand from there as your experience grows. You'll probably have better luck growing a cherry tomato in a pot outdoors in the summer and then bring it indoors for the winter and toss it out when it goes down hill - it may last all season but they usually get disease or insects before March. I can never get regular tomatoes to ripen when I bring them inside but cherry tom's do fine. Most of the herbs should do fine except the rosemary - in my experience it hates living indoors. Garlic is a seasonal plant that you plant at one point in the year and then harvest half a year later. It is not something that you can harvest off of all year long (there will be a plant but there won't be a bulb). Garlic chives should do fine in a pot indoors though and the flavor is similar. Asparagus will be tricky since the plants get 6 feet tall and about 4 feet wide and they pretty much like full blazing sun - I move them to the outside plant list. Carrots might work but they take more than one season to size up for me. You could grow seedlings all winter that you could then plant outdoors in the spring. Orange trees and other citrus would work and most will stay small when grown outside of the tropics. They can get buggy but if you move them back outdoors in the summer you may not have a problem. Most citrus bloom during the winter or very early spring and then it take all year for the fruit to form and ripen - making them a great winter time crop when no other fruit ready to harvest. They don't need high heat (I keep mine just above freezing!) but they do like higher humidity than what most people have in their homes.

The "two zone hardier" rule may have some validity as a very rough guideline, but it really is one of those enduring horticultural myths that never seem to die. The original poster is in Z5. According to "the rule" he ought to be able to easily grow Alberta spruce (Z2 hardiness and 3 zones hardier) in pots. Fifty percent root death for Alberta spruce occurs at -10. Several days of Z5 temperatures in the -15 to -20 range will kill it for sure in a small pot. Other plants are even more subject to root death. Magnolia stellata, for example, is generally considered hardy to Z5 or Z4. Fifty percent root death, though, occurs at +23 degrees. The thermal mass of in ground planting regulates temperature in a way a pot simply can"t. Zone listings are low air temperatures as measured over time. Root hardiness, except for the obvious causal connection, is a seperate issue.