Adding Android App to Google Play Store

Step 1: Create a publisher account: To create a publisher you should have a working Google Account. Google charges one time fee of $25 to create a publisher account.
You can create publisher account on https://play.google.com/apps/publish/ by paying $25.
Once you pay the fee , your publisher account will be activated in 24-48 hours, if not contact to Google Support.
Step 2: Once you your account is activated you can publish any number of Android Application in through your publisher account.
Step 3: Before you publish your app you must have a .apk file signed by private key and you must secure the key because the key is the only way to update your application in future.
Step 4: Open https://play.google.com/apps/publish/ and sign in your account, and click on "Add New Application" Button.
Step 5: You will be prompted to Give the Title of the application, Give a good title for your app and click on Upload apk.
Step 6: Upload your signed .apk file.
Step 7: Click on Store Listing button in left pane and upload all the required things like App Detail, Snapshots, Icon etc.
Step 8: Click on Pricing and Distribution: Select the Countries in which you want to distribute your app. You can distribute you app free of cost or you can fix a price for your app. To distribute your paid apps you need to create a merchant account.
You can create merchant account Here. Google Wallet Merchant Center.