I too would recommend that you speak with a local real estate expert to see what the implications are in your particular market. In the Charlotte NC area, pools are either a blessing or a curse. There are buyers who would never consider a house with a pool from a liability and safety standpoint, and also buyers who insist on getting one. From an appraisal standpoint, you won't get back what you put into it, so the numbers don't reflect the total cost. Hope that helps!
Gina- In Southern Ca.. at best the value of a pool is neutral. People either love them or hate them. Many couples with young children are afraid to have a pool. If you want a pool because you are an avid swimmer then go for it... but if you are thinking of putting one in as a value added item.. I'd pass.
A pool also requires a lot of effort and expenditure on an ongoing basis just to maintain it for the summertime. That's probably why most experts I've talked to about this often say a pool doesn't add to a home's value.
In my area, you don't add value for a pool because there are many people who don't want one; people with small children especially. A house with a pool can be more difficult to sell. You really should speak to a local realtor about that.