Alexa Skills are the way to extend Alexa, either to integrate with another service or to add new features. Before you can create an Alexa Skill there are a couple of things you have to do.
- You need to register at the Amazon Developer Portal. This will likely require an Amazon account, which you most likely already have. This lets you into their Amazon developer portal, which also covers Fire TV and Fire Tablet development privleges.
You can do this on your Windows, Mac, or Linux computer. You only need a web browser and your favorite editor. That is because you don't need to execute anything on your own system. The downside to all this "do it in the cloud" is that you need to go through some effort to duplicate the hosting environment to debug the skill. There are aways around this, and as the development environment matures, we are bound to see tools which make skill development easier.
Once you have those out of the way, you can deploy the code to AWS and set up information about your skill, including the voice commands used to carry out commands and be able to test them on your very own Echo (or Echo simulator).
Amazon has many Examples ready for you to deploy and review. Start with one of the Examples that sounds the most interesting to you. You'll find TEN examples, so check them out. HelloWorld example is always a good place to get the bare bones minimum example of creating a skill. ReindeerGames skill demonstrates a trivia quiz. WiseGuy will tell jokes. If you would like to see how to do a flash card skill see ChemistryFlashCards. TidePooler will scrape content from a remote web site. Here is a great summary page that gives you an idea of the concepts you'll learn in each example.
They all require about equal skill, and you will learn all the information you need to provide. You can (and should) use your own Alexa device (Amazon Echo, Dot or Tap or FireTV) to test out your Alexa Skills. If you want let other people use them, you must the Skil to Amazon for certification.
AWS Not Required
You don't have to use AWS to hosting your skill. However, you must find a host that can serve secure content, specifically over https. It means you need to get a certificate and do some additional setup.
I hope this gave you some useful information about how to become active with writing your own skills.