Part of the AudacityForBlindUsers section of the Wiki.
First of all, be sure that you learn all of the keyboard shortcuts that do not correspond to menu items. For example, hit the spacebar to play or stop, hit 'R' to record, hit 'P' to pause (pause is not the same as stop, make sure that you hit 'P' to unpause otherwise you won't be able to do anything). The Audacity user's manual has a list of keyboard shortcuts.
The Keyboard section of the preferences has a complete listing of keyboard commands, and allows you to change the shortcut for each command. (Are these keyboard preferences usable with screen readers?)