Craigslist is a drag. Most of the time (in most places other than a few major US cities) you find absolute garbage listed there. I've had almost zero luck selling quality drums on Craigslist.
eBay is great and you'll very likely get more for your gear that way, if you list it well. Clean your drums up and take excellent pictures in good lighting (outdoors is great, too.) Don't expect to make back 100% of what you put into them. Check what other sellers are listing the same gear for and be competitive.
Craigslist for sure, but it probably depends on your area.
eBay may be okay if it is a really rare or hard to find item, or if you're in a very remote location, but I prefer Craigslist for buying and selling for a number of reasons. You can see the item/show the item in person, which is especially important with music gear. You also don't have to package it/ship it/worry about your packing job if you are the seller and you don't have to pay for shipping if you are the buyer. Most everyone uses it and, most importantly, it's FREE!
I sold my very first set to a cousin of a friend of mine. Never hurts to ask people you know if they or someone they know is looking to buy something.
Then again, this was a beginner set, which I imagine is a lot easier to move than a higher end kit.
+1 for Craigslist. I've never sold drums on it but I've had success with selling a couple of guitars and bought a slew of gear.
Fun story for you: Called a guy about an LP cowbell a few months ago. I planned on dropping by his house before my gig as he lived right up the street. Long story short, I had him meet me in the parking lot of the venue 10 minutes before we went on. I used it on every song that night and had the crowd help me name it. Bessie.
Anyhoo, I'd recommend taking some good pics as mentioned before, put all the obvious information they'd want to know. Importantly, don't put your e-mail, you'll get flooded with spam about "making money from home!" Drum kits can take a while to sell with the recession and all but you're not going to pay shipping costs and you're getting paid in cash up front.