A lot of the folks here take PayPal which is the easiest and most convenient way to pay. Some other take checks and money orders but kinda check'em out a little before sending it that way, for most of the folks it won't be a problem but there are some skunks that sneek in! 8)
Personally, paypal is my number one choice when paying or collecting, and then cert check, which is no safer than a personal check any more. They are faked more than anything now days.
Watch the guys saying they will send you a certified check for over the amount and want you to send them the diff back. Somehow the check seems to clear after a few days, but the bank always comes back on you a week later for the bad check.
Electronic payment is the safest, but you still stand the chance of the guy not shipping it to you. I have done hundreds of on line transactions, and only been burned one time, by a newbie kid that I didn't call, and when I asked for pictures of the item, he couldn't produce any, which should have been my first flag.
How ever they prefer. Most people are honest on here. Ive sold, bought, and traded on here. Ive sold and sent things out before I recieved the money. (must be a member thats been here awhile) And sellers have done the same for me.