How do I start a successful pool maintenance business?

The business seems very lucrative in my area , but, what would make my services ,other than a lower cost, more appealling to prospective new customers.

follow the business strategy

If you sell on low price only, then you better be able to produce a lot of product or service, and with this type of service I don't know how you can produce more service, you'd still have to hire people to do the extra work.
Instead you might think about being more creative in how you introduce your service to people. Such as: Go to party hosting companies and caterers, whose specialty is hosting outside parties, this way you know the owners are going to need their pool cleaned after the party. Offer them a first time discount for trying your service as a benefit of hiring the party service, this way the party service gets something out of it for offering your service to their customers. This will get your name in front of people who truly need your service, but might not be completely happy with their present service company. Secondly, offer package deals, maybe if (4) neighbors on a single block sign up with you, you give all (4) of them a discounted price for saving you money on gas for your vehicle; or you offer a package discount for people who sign up for weekly service for the busy season, as well as bi weekly for the slow season, thereby assuring you of business in the slower time of the year.
The key is be creative and don't just start with discounting your price right away, you deserve to be paid fairly for your service and if you demand it, you're get it.

Do not just compete on price, perhaps emphasize superior customer service, or response times.

Use this basic checklist to make sure all the important steps are taken before you launch your new venture. This business checklist will make sure that you cross all your t's and dot all your i's before your business launch.

Steps to Starting a Business -
http://www.developer-resource.com/starti...

Other sites you might find helpful are:
SBA - http://www.sba.gov/
SCORE - http://www.score.org
Small Business Resource - http://www.small-business-software.net
Business Link - http://www.businesslink.gov.uk/bdotg/act...

Goodluck!

take some marketing classes.