You'll have to get a feel for that. Try to get a member of your state's fruit team, if you can. They should at least know the difference between a pollinator and a pollenizer. Incidently, a visit to your county extension office will usually get you a briefcase full of free information on fruit growing. Or go to the state extension web site.
Some states are better than others about getting information online.
To find that, go to your state land grant university, and try their own search engines for various fruit topics. Plant your trees as early as the soil can be worked. There is about a six week span that you can plant, and have the trees survive. But planting early in that span will gain you the equivalent of a growing season. Plan your pollinizers when you plant.