Agree that Autotrader is the way to go. Get the car perfect and take some good photos to upload with the ad. Go through all the ads for cars similar to yours to check pricing, and also check it on Parker's.
Checking insurance is OK, but it will be 3rd party only on someone else's insurance, so no claim if they damage it during the test drive.
Best way to organise the money is by banker's draft, but not direct from the buyer. Get the buyer to arrange collection of the draft from the nearest branch of their bank to you. Go with them to the bank and get the cashier to hand it directly to you. Lots of forged draft's around, and personally I don't like huge wads of cash as you can't be sure they are genuine