Get a refresher on chemistry and more
Are you familiar with the Khan Academy? If you aren’t, you should be!
The Khan Academy was started by Salman Khan in 2006 with the expressed mission of “providing a high quality education to anyone, anywhere.” And he does just that.
Take a look at the chemistry lectures. There are over 100 high quality talks about various chemistry subjects.
If you are looking for a refresher on chemistry, this is an excellent place to go and it is all FREE.
Of course, most of this won’t directly apply to cosmetic chemistry (that’s why we’re here) but if you’re looking to get caught up to speed on basic chemistry, this is a great place to start.