MIke, there is a lot of info on this in the archives. Try searching and see what pops up.

The knock on cotton is that once it is wet, it loses all warmth and stays wet. In dry, hot weather, I would wear a t-shirt if I didn't have a fancy synthetic. Wool, on the other hand, will keep you warm even if soaked. So will fleece.

Levis are bad for all kinds of reasons-not all that warm, heavy and worse if they get wet. I'd rather wear nylon wind pants or something similar.

I don't do much summer camping, but you can buy all sorts of synthetic hiking clothes for summer-similar to biking or running gear-Coolmax is one brand I have seen.

Get an REI catalog or look online-go to the Portal (the colored link at the top of the forums) and look at the online stores.

For underwear, I have some synthetic briefs made by Jockey. For cooler weather, I have a midweight Capilene top and bottom. For socks, I have some Thorlos, Smartwool and some lighter ones.