Thinking about starting a business

I was thinking about starting a small business involving putting POIs on gps systems and selling them to tourist areas. Does anyone know an easy site to create and load custom pois?

When I create the files can I load them into an easily accessible file that the tourist can open and search for pois?

Say I create and load a POI for a certain attraction, if the tourist searches for the attraction name will it show up on the gps?

Any input that you would have would be really helpful.

Thanks for your time,

Rambo