In my humble opinion, it is best to use fruits that are in season. At this time of year that's really slim pickin's. Fresh seasonal fruit will impart the best taste, whereas things that are produced in a greenhouse are sort of forced to grow in unfavorable conditions. This difference is not as noticeable when you are snacking, but is very noticeable in things like brewing and cooking. Your choices right now are citrus: Meyer lemons (if you can find them its a cross between a tangerine and lemon), juice oranges, grapefruit (which are expensive this year) and kiwi. Peaches and strawberries will be a waste of your money, but frozen blueberries may be a good bet if you want to go that rout. There is a good thread on here about brewing blueberry cider, its actually pretty interesting. There will probably be some dissenters chiming in soon suggesting that I am wrong, and that is fine. I am in the middle of brewing a batch of cranberry cider with fresh cranberries (which were in season). I used 4 bags of OS cranberries to 5 gallons cider plus 1# wildflower honey, 1/2 lb. buckwheat honey, and 2# brown sugar with Safale 04 yeast. I decided to cold crash to preserve some sweetness. I had it at 7.25% ABV and it was far too sweet so I added 1/2 tsp citric acid and 1 packet Red Star Champagne yeast to restart fermentation and dry it out a bit. I regret not using even more berries than I did. That's where I'm at now. Basically my point is, I guess, don't waste your money on out-of-season fruit that is all starch and low sugar. If you want to spruce up your brew a bit, consider Wintery things like orange peel, coriander and cardamom (an awesome palette-confusing additive). If you want to use strawberries (June) or peaches (late Summer), buy them locally, wash them and cut them and freeze them yourself then wait for cider season and then bring it all together.