Error 500 hypertext tranfer message, amoung others

Hello all, hope you are having a fine evening. I recently enrolled in college and I've been having a heck of a time navigating through their web pages. I get a lot of: Internal Error message 500 hypertext transfer protocol. I tried their tech support which advised me to add them to "trusted sites," which I did and it helped some. Once in a while I get to where I want to go without any problems, but most of the time when I try to navigate in the secure pages I get various error messages and have to start over, and I can never get any printer friendly pages to come up. Any Ideas? HELP! I'd sure like to get this figured out before my Summer classes start. Have to use black board for some of the classes, which I have to get to from the same log in page.
Thanks, Jim