Answers

Start by doing some research for your local area.

What type of pools work best for your ground condition; Gunite, Fiberglass, Vinyl Liner, Above Ground, etc?

If it is gunite, what style do you want; Freeform, Geometric, Lagoon, Modern?

Do you want a spa?  Do you want a waterfall?  Do you want to heat your pool?

What materials catch your eye?

Create a portfolio of pictures of pools that you like, this will help the designer really understand waht you are looking for.

Check out the companies that you call.

How long have then been in business?

Are they members of BBB?  Rating?

Do they have an office or do they work out of their house/truck?

DO they have insurance?!?

In the Houston Metro Area our customers expierience an annual cost of about 1,500-2,000,  this includes electrical, gas, and chemicals.  

These numbers represent an average sized pool, average spa usage, and properly maintained pool chemistry.