Where's the guide on how to measure IC pin voltage?
Not sure that there's not a guide for that specific task per se. See here for how to measure voltages: http://www.madbeanpedals.com/forum/index.php?topic=902.0
Measuring voltages on IC pins is the same process as measuring voltages anywhere in a circuit.
IC pins are labeled ... according to the datasheet. No, seriously, the numbering progression is standard, but look up the data sheet anyway! It will tell you what the pins do. This can help you with your troubleshooting.
Also, it's often easier if you have an "alligator clip" lead you can use to clip the 0v lead of the DMM to a known ground point in the circuit/pedal. It frees one hand to adjust meter scaling, scroll a page on a website, hold a magnifying glass, turn some knobs, whatever.