The smallest chainring you can put on a "compact" (110BCD) crank is 33T and usually the smallest reasonably-priced one is the 34T. I've often thought that a 46/34 double with a 12-28T cassette would be a great starting point for most people*. That's 32-101 gear inches if you're using 700x25 tires.
You should play around with this site if you haven't already:
http://www.gear-calculator.com
* More appropriate than the common 50/34 crank with 11-something cassette that gives you a 120" high gear and makes you cross-chain for the usable combinations...