This right here. This link. This is the single most important link you ever need to have.

The Beer Judge Certification Program lists 100 styles with defined ranges of alcohol by volume (ABV), bitterness (measured in IBUs, or International Bittering Units), and color (measured using SRM, or Standard Reference Method).

... and that link up there will take you to a mapping of every beer you could be consuming.

... oh - and talking of the other Beer Maps - I bet if you did this walk, the chances are that many of these delights could be sampled on route.

Enjoy.