I just found this site yesterday. Evidently $30 gets you all the answers to your questions ...

http://lavenderalbino.com/Home_Page.php

... I haven't bought the video, but might do so once I buy an ultrasound next year. I'm sure the settings are pretty straightforward, and I'd imagine the technique is too, but I haven't been able to find much information on how to use the information gleaned (follicle size and number) to plan breedings.

Unfortunately you may or may not be able to find a vet tech who is skilled at ultrasonography to show you the ropes -- many private practices hire outside ultrasonographers to come in once to a few times a week, and don't own their own unit, so their techs may not be trained in how to use it.