1.) That's a broad question, many styles of beers taste better after conditioned in the bottle for months, (I especially have this experience with a lot of fuller bodied, and belgian style beers), and IPA's, and more hoppy beers tend to taste better fresh IME. There isn't really a time table, perhaps some decent practices for different types of beer.
2.) Most dry yeast the recommended temperature is 46 degrees F. I ALWAYS put mine in the fridge or freezer.