I agree with Denninmi- watering over the summer will be very important, especially for blueberries. I'd suggest using a soaker hose/drip irrigation to take some of the work out of it. As far as a good nursery which ships potted plants, I would suggest Rolling River Nursery. Their prices aren't much higher than bare root, so I've been doing more and more of my buying there (I bought from 9 different nurseries this spring). Berries Unlimited (3 gal blueberry plant is very nice, but very pricey), Backyard Berry Plants, and Whitman Farms are 3 other choices who ship potted berry plants. I don't think any of these sell apples and plumbs though, so Rolling River would be my suggestion for those. It would however limit your rootstock and variety choices a bit.

I have and RdR in a pot that I've wintered (outside, don't have a garage) for 5 years now and it's done just fine. But if you intend on putting it in the ground it might be best to do so now rather than waiting. Plant it deep, deeper than it is in the pot by anywhere from 4 to 8 inches, and mulch it a good 6 or 8 inches high or even higher if you can. And try not to disturb the root ball at all when you remove it from the pot to put it in the ground. If you decide to keep it in the garage there are two things you need to do. First, get the pot off the cement floor by putting it on wood blocks. Concrete is like a sponge and will suck the moisture from the pot as well as transmit temperatures. Second, do water it! Make sure it is well watered going in and about once a month either give it a drink or put a shovel full of snow on top of the pot. It doesn't need a ton of water but it does need to stay hydrated. It isn't how low the temperatures go that kill them but the rapid up and down change of temperature and the drying out (desication) that does them in. Rose de Rescht is one of my favorite roses. Lovely pink blooms with a button center and a heavenly scent! Enjoy yours!

Green, or English, peas should already have been planted, and should be flowering and/or bearing peas now. You could try planting them now, especially since we've been having all this cold weather. But if things warm up and stay warm, you might not get any peas because it might be too warm. English peas are a cool season crop. Beans are different. They like warm soil. If you put them in the ground and it's too cool, most of them will eventually sprout, but germination won't be as good as if you had just waited for consistently warm weather. Also, it's possible to stunt the growth of your bean plants by planting them too soon, if we have cold spells after they've started growing. This is especially true for lima beans. (I'm not so sure about green beans as I don't grow them). I always wait until May to plant my climbing lima beans, and even then I'm not in a hurry. When they sprout and start to grow, they'll more than make up for lost time. And since I plant climbers, they'll continue to produce beans all summer, right up to the first hard frost (and sometimes even after that, if I can get them covered or if they're growing in a protected area). Field peas (crowder peas, black-eyed peas, and the like) are also warm-season crops. They, too, should be planted after the soil has warmed up and the temperatures are consistently warm. The way things are going right now, it's anyone's guess when that will be!

I would plant now, but if you have a whole bunch, why don't you plant some and hold some, then see which ones do the best? Laetitia