on 4 May 2002
The tables of common integrals and derivatives make life wonderfully easy! Not advocating cheating on homework, but if you ever get stuck... Lots of other useful stuff too. Probably best suited to the college/university maths student though, there's a lot of stuff mere mortals will never use!
on 7 July 2008
I'm now on my second copy, having used the first so much that it fell apart. It's not as detailed or as comprehensive as the Handbook of Mathematical Functions by Abramowitz and Stegun and its statistical tables are also somewhat limited. That aside, however, it is excellent value at the price and unless you are doing serious numerical computation or advanced statistical work, this handbook may be all you'll ever need.