I took the direct advice of an outdoors columnist here in Minnesota, with one exception. I don't knock on people's doors. I like my privacy here in the city, and do not like to be bothered. So, to locate good areas of the state, I would buy supplies at the small local gun/tackle shops (not the big retail chains) and ask the guys where a new hunter should be looking. I would get good info, and was told to focus on older farms, not the suburbanites that just moved out here. Anyway, when I see someone outside working, I give em the wave, and when I get a response I drive in to talk. "I'm a new coyote Hunter and the magazine says there are farmers that may have a coyote problem. If I ask, they may allow me to hunt on their land. Would you allow me to hunt coyotes on your land? Here is my card. I do not use dogs. I sometimes will have a partner. Does it sound reasonable to let you get your crops in and finish deer hunting season, then I come back and you give me the tour? I will always call ahead of time, and will give you my vehicle plate number."
That worked for me, and I have treated very nicely by all. I got 5 spots this summer. After I get there and check it out, google earth shows me where the swamps and forests are, so I know which other neighbors I will ask next. The most common answer I received was, "I already have a group of guys that run dogs through this area at night." These guys were also friendly and tried to help by telling me where else I would strike out and where else I should check.
I will tell you what started this whole thing. My idea was roadside sweet corn stands. That corn came from a farm and the guys selling the corn know the whole county and exactly where to send me.
And like what was already suggested, saying thank you at every opportunity. Fine cigars and fresh pies at the end of the season.
Anyway, that was fun driving around, talking to farmers and seeing parts of my state that I hadn't seen before. NOW I'm ready for the really fun part: shooting my first coyote! The snow is here and the temps are dropping.