I have made a application in android with map view and I want to publish it on market.
So first of all how to export final APK from eclipse and second Google map API
Release: right click on the project, go to the android tools, choose the option that reads something like "export signed package". For the key, sign up for one. It really boils down to that. But the complete manual/helps are online, and easy to find.
I wonder where you're stuck, but just read these topics:
Signing Your Applications
Versioning Your Applications
Preparing to Publish
Publishing on Android Market
(I've linked the first, the rest are on the left hand side of that first link).
For the google maps API you'll get far enough using this link i presume