It is good Netiquette to be careful accepting checks. Do verify availability of funds.
Check Netiquette Classifieds
As a seller of an item in an online classified post you are a merchant. Following merchant practices accepting checks may prevent being scammed. Ask for identification.. Copy the license number onto the check for identity verification. For funds verification call the bank listed on the check. They will be able to tell you if the check will clear.
Money orders, personal checks, and financial instruments can be forged. Positive identification, funds verification, and the price of an item are major factors to consider when accepting checks. Out of state checks are not generally accepted.
Be careful accepting checks because there are many check scams.