GPS Coordinates (no replies)

Hi All

I am just entering the GPS coordinate data storage and programming. I know nothing about it. I have a few questions:

1. What is the best data type when storing the longitude and latitude?

2. If it is a number such as a real are there functions to convert this from the number to a string to present it in human readable form and from that back to the number?

I know nothing about this so excuse the stupidity of the question.

Cheers
André