We have a stamp collection that was my father-in-laws he started in during WWII. We would like to know what our next steps would be to find the possible monetary value and where to sell them.

The stamp society has drop-in hours on the 2nd and 4th Saturdays of the month from 10-3 or there abouts. They always seem happy to look at what you have and will honestly tell you if it's a collection that has value. And it's a free casual appraisal. Depending on the era of stamps, the topic, country and/or the condition, they have many folks that have different levels of expertise. If the stamps are rare, I'm sure they will be able to direct you to an appropriate buyer. Tomorrow would be a good time, as I believe they will be open. Good luck!

I would check their website for some sort of email or phone number, I go here for a club meeting once a month that's not stamp related but it's an obviously used place... sorry I couldn't be more help, sounds like a cool collection though!