Hiring a contractor? Making a major purchase? Here are a few "dos" and "don'ts." Do use local businesses; transients often disappear. Don't take the first bid; shop and compare price, terms and hidden extras. Do read all fine print on contracts; ask about anything unclear. Don't sign a contract with blank spaces. Do save all contracts, receipts, cancelled checks and warranties. Don't pay cash; write checks to the company, not the salesperson. Do check with the Better Business Bureau and city and state licensing boards. Ask about insurance. Don't accept oral promises; get everything in writing. Do remember that the ?cooling-off? rule lets you cancel most contracts within three days; don't be pressured into hasty decisions. If a terrific offer expires in 24 hours, let it. ?Business? is a tricky business and you have to be careful when doing it. Always take two trusted friends with you when you shop -- caution and common sense. And that's the On The House tip for today.