You can feel reading this text that i am explain nothing about code. Ok it is right. I dont mind to explain developping techniques, i want to tell you steeps to get an extensin from the begin to the market.
Lets see... now you have a extension which you can add a button to a web, por example. Now its time to share it and start ti test for bugs. If you try to do it alone its imposible.
The best way is to tell it to your friends in G+ for example. Firstly you must to upload your crx file to Gdrive and share with your friends the link to this file.
How can i get a crx file?. the answer its very Easy
You must access to the extension properties page and you must check the developper mode. Now appears new buttons. One of them is "package an extension". If you click here you will be asked about the folder extension, and about a private key. If it is the first time, you must to leave blank the private key in other case you must to link to file generated first time, if you want to Chrome detects this as extension update.
After that, you will get a crx file. Now you can host this crx file where you want and share the link with your friends.
In the next chapter will learn to get automatically updates.