Don't Go to the Cosmetics Counter Without Me by Paula Begoun (2003, Paperback)

This book contains all the information you need to make an intelligent and informed decision regarding the cosmetic products that you buy. The author goes into incredible detail about the ingredients in various products, what does and doesn't work and why, when it's worth spending a lot of money for high-end brands versus buying from the drugstore (virtually never!), etc. She covers every brand and name you can think of. There is a later version, but this one contained all the products that I needed to know about. If you have a choice, I recommend buying the latest version you can afford, because there are always new products and ingredients coming out. She tells you which ones are good for your type of skin, whether they contain enough or the right combinations of ingredients to be effective, and much, much more. Definitely worth having in your library. Will save you money if your follow her advice.