Publishing an app on Google Playstore is very easy. Just follow the below steps.
1. Go to to the Playstore Developer Console - https://play.google.com/apps/publish/
2. Now enter some basic information like your name, address etc.
3. Then read and accept the Developer Agreement.
4. Then pay $25 as a registration fee with your Google Wallet account. This is a one time fee. You can't use your AdSense account to pay this fee. Only Google Wallet account is allowed to do so.
5. Once your account is verified via an email, then you can upload Android Apps and Games on Google Playstore.
6. Every App and Game is first reviewed before getting published. It may take 24-48 hours.