Old post brought up by a spammer, but I figured I'd share anyways.
First, go to
https://valueguide.pga.com/ to get a value. If you want to sell them quickly, price them lower. Post them on Craigslist and Facebook Markets (3 years ago I would have just said craigslist!). GolfWRX is good as well, but often involves shipping. Then take a TON of pictures. Show the worst clubhead, front, back, bottom, top. Show the 5 iron, show all of the clubs together, show the grips... For a set of irons, I've probably got about 12-24 pictures.
Certain irons are going to hold value pretty well - Ping EYE2, any BeCu Pings, certain Titliest and Mizuno's... While others will drop like crazy. Don't hold out for top dollar for a set of 20 year old Cobras. Probably not much of a market. Putters will hold value better, especially Camerons and TP Mills (and some others, those are just the easiest I've found to sell).
Woods, including drivers, are the tough ones often. It is the club more people replace with regularity, so not a lot of people are looking for one.
If you need an imediate sale, go to Golf Galaxy or 2nd Swing or a pawn shop or a Play it again sports. May or may not get enough.
Back to your regularly scheduled spammers.