What do I need to start?

PADI Open Water Diver certification (or qualifying certification from another organization)
PADI Advanced Open Water Diver certification (or qualifying certification from another organization)
PADI Rescue Diver certification (or qualifying certification from another organization)
50 logged dives
Five PADI Specialty course certifications
Minimum age: 15 years old (12 for Junior Master Scuba Diver)

Where can I go from here?

The PADI Master Scuba Diver certification is the highest recreational level in the PADI system of diver education. But, you don't have to stop there! You can continue on to become a PADI Professional. As a Master Scuba Diver you'll be well qualified to begin your training as a PADI Divemaster.