Math skills are becoming more and more essential, and I wonder where is a good place to brush up on some basics before moving on to some more CompSci specific stuff?
A site with lots of video's as well as practice exercises would be a double win but I can't seem to find one.
It depends on your math level. You should start by revising what you should know till that moment and then go further to algorithm mathmatics, geometry (transforms and etc), statistics and more.
There are tons of places on the internet were you can learn:
http://www.math.cornell.edu/Courses/courses.html
http://ocw.mit.edu/OcwWeb/web/courses/courses/index.htm
and the list is open.