The Better Business Bureau of North Alabama give some great tips when you begin Spring Cleaning.
Know who you are hiring.
Take time to research the person/company and if they are licensed and insured/bonded.
Read your contract then make sure there are no spaces where extra information could be added without your acknowledgement.
If the deal sounds too good to be true it probably isn't.
Don't pay for the job up front. If money is needed for materials, perhaps pay a portion or buy the materials yourself.
As always the Better Business Bureau can provide savvy consumer information. Call (256) 850-0719.