Dear Pam,
In my opinion, the thing about makeup, foundation etc. depends really about the kind of skin you have. I actually wear makeup all the time, and I rarely use all of the above.
Basically, what makeup and the other stuff you mentioned are designed to do, is to even up your skin, remove signs of humidity and/or any imperfections. What I found very useful is actually using only powder. What i use, is Boaz Stein's powder. It looks white, but in fact its transparent and therefore suitable for all skin. If you intend to apply eye shadow as well, the powder will help it spread evenly, and stay on for much longer.
If you're not used to wearing makeup I would add just blush, and mascara - believe me - they do the trick! 
So, good luck and more important - enjoy it!