How should I measure my 60 second resting heart rate?
The usual recommendation is to just pedal slowly and then take the measurement. If your recovery rate is 12BPM or less, you should go see a doctor. A very fit person would recover 40+BPM. Someone who engages in regular cardio exercise would probably see recovery rates of 20+. 

This is a HRM function that I use only a few times a year; like when I get back to real rides in the spring. It's probably most useful for either someone in training or a person starting out on a cardiovascular fitness program. 

There's a chart on the wiki answers link.

http://wiki.answers.com/Q/What_is_a_good_Recovery_heart_rate_level

And another:
http://www.drmirkin.com/heart/8076.html