I would advise you to have a look at the "Piggott" wind turbine. These are turbine that you can build and assemble from standard components with a bit skill and few friend or neighbors to rise the pole.
They are also more performant than most commercial small scale wind turbine that you can buy.
Even if you end up buying a commercial turbine I would still advise you to get the book, it gives a lot of information about wind turbines, and it's probably one of the best source of information for small scale turbine available.
One thing really important of course is to have regular strong wind. You can have a have a general idea of the wind in your area using Global wind atlas.
But wind can vary a lot in the same area so before you commit to installing few turbines, if you want to make sure tge investment is worth it, I would definitely advise you to put an anemometer on a pole at 1.5 time the high of the surrounding obstacle close to where you imagine installing the turbines. And wait a few months or ideally a year.
From this data you will know how much energy you can expect from wind turbines.