I laughed all the way through dj's description, the only place I thought it a bit weak was in describing the force the cow can exert on your arm! lol Some of the most frustrating times of my life! And then you pull your arm out and what do you get! ( If not quick enough! ).
Do the search dj suggested, and I suspect your gonna see a lot of stuff you may not understand ( synchronizing, heat detection, etc.. ) and then come back with more questions.
A simple answer to one of your questions is that many farmers both dairy and beef do their own AI. It usually involves taking a course ( mine was 5 days ) and several dozen simulated inseminations under instruction and dozens more practice inseminations.
Depending on how many head you are running it can get expensive to do your own, but there are costs with a bull as well. You should have semen distirbutors in your area, and if you buy from them I think it is about $14 a head for the tech if you do the heat detecting.