Here are some questions you should ask fence contractors before starting the job.
Are you bonded and insured?
Do you have workers compensation insurance? Due they have a business license? Check their license out at the Contractors State license Board.
Will you be hiring any subcontractors?
Are they familiar with local building codes, pool codes and the fence permitting process? Can they point you in the right direction to find out this information?
What is their payment schedule? How much do they require you to pay up front? In the state of California it should not be more then 10% down or a $1000.00 deposit to secure the fence job
How many workers will you have on the job?
How many days will it take you to finish the job?
How long till you can start the fence repair/replacement?
Where do you get your materials and lumber?
Does your estimate include materials and labor?
Will I have an official copy of a detailed & signed contract?
If there is grade (slope) to deal with? How will you deal with this? Will the fence be "stepped" in sections (thus leaving triangular spaces under the fence or will it contour to the ground?
How will the fence contractor work with any obstructions like trees, rocks, etc.
What kind of warranty do you offer?