Generally trees that have a stone, like peaches and apricots are self fertile, but not always, that means that the bees can carry the pollen from one bloom on the tree to another bloom on that tree, and it will produce fruit. It doesn't affect the taste of the fruit. Apple trees usually need another variety to cross with that blooms about the same time. Most pears need another variety to cross with. There are a couple of sweet cherries that are self fertile, the Stella, and Lapins. Of the two I'd recommend the Lapins. I have a Stella, and it seems to be susceptible to some diseases. If you don't have a lot of room, you can plant a dwarf about 15 feet apart. They are easier to prune, and spray, and you can pick the fruit without a huge ladder. If you do a lot of canning, and preserving, then you might want larger trees. But if you use the fruit fresh, you might not want large trees. Here is a link to Grandpa's orchard. It is a great place to buy quality trees, and there's a lot of information as well.
http://www.grandpasorchard.com... They give you a lot of information about the growing zones, and desease susceptiblity, good keeping fruit, etc.
These are the apples off one standard size tree (Bonnie Best variety) I really like these Bonnie Best apples, they make the best pies, and apple sauce of any. They keep fairly well too. The only place you can get this variety is from Jung Seeds and Plants here in Wisconsin. I had picked a quite a few of these and gave them away before I finished picking, so this isn't all of them.
These Granny Smiths came off of one Semi Dwarf tree.
These peaches came off of one Contender Standard size tree, which I keep pruned down a lot to avoid high ladders. Most peaches require thinning, or you get small fruit.
Good Luck!
