Price you car based on combo of prices seen here and on cars.com or autotrader and other pricing guides. Note cars.com and autotraders are retail prices, and can have subtantially lower transaction price. You should note the private sellers' prices on those sites.
As with private buyers -
If buyer plans on giving you a personal check, you need to coordinate with buyer well ahead of time to ensure buyer has sufficient funds. You can request the check earlier and call buyer's bank to ensure sufficient funds. If buyer shares same bank with you, both parties can go to a local branch and simply do a fund transfer on the spot.
Most buyers will likely take a loan out with their bank/credit union to fund the purchase. This buyer will show up with a bank check for you on pick up date. I suggest, having the buyer email you a scanned copy of the bank check before he comes to pick up the car. You need to then call the bank/credit union on the check and ensure that the check is not fradulent and the loan was indeed given to the buyer for the purpose of the buying the car. Buyers who need the loan generally would ask you for the VIN number first before they can even get the loan from the bank.
Of course, on your end, you need to give buyer his keys, manual, and title. Not sure how it works if current title has a lein on it, you'll need to ask the lien holder how to resolve the situation before the transaction. (some states doesn't even give you a title if there's a lien on it)
I think depending on the situation, you'll get better price if you sell privately on this forum. I don't suggest selling a car to a dealer if you're not buying from them, they have no incentive to give you the best price. But if you must, I've heard that Carmax gives good prices for straight sells.