I'm embarrassed to be asking this but I'm in need of a little guidance. I'm about to start some experimental work and I need to think about the number of samples to take and even tests to run so that they are statistically significant. Obviously more is better but the tests are time consuming and expensive so I need to limit them. Can anyone point me in the direction of figuring out this?

I've done a google search multiple times but I seem to just be getting more and more confused :$

I'm not entirely sure if I understand your needs (I'm social sciences) but I used G*Power to calculate the sample size needed in order to test for significance.

Hi Ev, I have some introductory books on this matter. If you PM me with an e-mail address, I would be happy to send them to you.

Thanks Delta!

And thanks Wally - you seem to have books on everything!!! I'll pm you right now.