I haven't done much selling in the past 8-10 years but as for buying I know CL is awesome...
As for selling,
1. Beware!!! Do NOT put your phone number in the ad. Put it in the contacts (as mentioned)This feature was only added recently. I've heard of programs that search numbers on CL for spam / advertising. You can generically google every craigslist in a state or nation wide by keyword "craigslist" / "North Carolina Craigslist" and such. Same goes with "Craigslist text or call".
2. Alot of folk won't bother without pictures, price and complete description.
3. Take a short break after you post and then go back proof read your ad. It's so easy to make a mistype that kills the ad for once someone reads an ad, it shows up "read" and they won't go back. A fresh eye picks up so much more when proofing.
4. Delete ad immediately after item sells.
5. If item doesn't sell within 10-15 days, delete old ad and begin a new one. Don't know how it works but I think there's a feature to relist now?
6. Be nice and polite no matter unless some asswipe starts something and keep track of people you talk to. What comes around / goes around. I learnt since a very early age to never burn bridges with folk you meet and you just never know where it will take you. Remember -reverse searching is easy by using keywords such as your location with maybe something else to narrow you down from here on. I wouldn't want to piss off the CL killer... LOL
7. Don't rape with your price. If an item doesn't sell, don't know about you but my "time" has a price (I'm getting paid hourly to sit behind a computer as I type now). do your research and knock your price down every now and then. Remember, no taxes and 95% will be local.
8. Specify if you will ship or not to eliminate that.
9. If selling alot, place a unique word for everyone to search and tell them "to keyword search (word) for other items". I use my internet nickname of "Gittinwidit".
For buying: It's a great opportunity for the "horse trader" type such as me that knows the current price on a given item / items.
1. Learn the search key characters. They are your best friend.
2. If you got the time, I find my best deals by searching backwards using a slew of "-" items and weeding out what I definately "don't" want first. And use the generic catagories such as "for sale" section that searches everything. That leaves the misspellings and wrong catagory listings and such. I saw 2 news articles lately where there's been entire businesses started by using this method. And keep a log of key paths if you buy an item frequently to save time for my search will be 200 characters long by the time I begin to start reading.
Being from out-of-state when it first started up (1993-4'ish?) and working with a very small company, I've met my whole realm of friends from CL and it keeps on growing. My last full time employer when I was unemployed during the recession, a part time side work employer now I met recently (shared a job this morning) and a partner (and best friend) for my landscaping business (3 years now and growing) all came from CL. My dogs. Most my furniture. All of my building materials / and a ton of it. My vehicles. My renters. And most importantly... 6 years and growing stronger every day - My wife.
I started a business parting F-100's when CL was first introduced and it became such a huge job (entirely on CL and ebay) I had to quit parting after 6-7 years of it since I had a 40 hour day job (with benifits) as well at the time. I was working night and day and all weekend. I made a ton off of CL...
I've met 2 local people recently that make their entire living off of CL today and good livings at that. One guy parts cars down in Fayetteville. He's non specific on what vehicle and knows what he's doing and makes enough for 3 helpers / partners.
Everybody uses CL now days as their employer advertising. It's now one of the top rated sites for employment.