You can look up the salary of anyone at the public university in California on this site:
http://www.sacbee.com/site-services/databases/state-pay/article2642161.html
It displays what they were paid, so it won’t list current or agreed future salaries. As to the question of coaches being paid by booster, I don’t think that that is really accurate. If they are listed on the data base then they get a check by the state. Athletic departments do receive significant donations that goes toward everything in the athletic department from facilities, to transportation, marketing, etc… and can be targeted to sports or position. For most athletic department they get more support from the school then they bring in through donations but the number of coaches that make over $200,000 is limited to a the sport and the school. The vase majority of coaches are underpaid, including the number of unpaid or low paid assistants at Division II and III and even Division I programs that are minor sports not at flagship schools. I also think it also should be noted that while some of the positions are lucrative, at the high paid level the length of time a coach is in that position can be pretty short, because the expectation is great.