Recently I’ve been reading “High Performance Web Sites” (look at amazon).
I think it’s a good book who can be recommended to all who do even little bit of front end development. The book describes 15 rules (regarding CSS, JavaScript, etc.) that should be followed in order to deliver high performance web sites. It’s rather short (c.a. 150 pages) and easy to read, but the suggestions described by the author can be helpful while you work.