I'll second the recommendation for the book. It is not the easiest going for the non-mathematically inclined, but I can say for certain that what it offers really works and lets you concentrate on making pictures. I can honestly say that when I have used the incident method described in the book, I have not had an exposure or development 'failure'. I'll also put a plug in for the palm pilot program that Phil Davis markets through the View Camera Store: it makest the whole process painless, and if you want to skip all the testing stuff, you can just use the built-in database if you use some common films and developers. I have found his data on Tri-X, FP-4 and HP-5 souped in DDX and D-76 1:1 to be very accurate right out of the box. In my opinion, Knowledge == Freedom.