For more information please visit https://developer.amazon.com/en-US/docs/alexa/ask-overviews/build-skills-with-the-alexa-skills-kit.html.  

Important topics for your to understand are the following:

• Build Skills with the Alexa Skills Kit
• Requirements to Build a Skill
• Understand the Different Skill Models
• Requirements to Build a Skill
  • Skill Model
    • Custom Skill Model
• Account Linking
• Alexa Interface Reference