What is the simplest way to create web service?

I'm planing to write some web service from scratch. The service must be secured & will massivelly use the DB.

I looking for framework(s) for completing such project without reach expirience in web developing.

It must be:

  • Easy to learn/use
  • Fast & iterative development
  • Scalable (the service can grow into complex project with huge db)  
  • Ability to upgrade the system on the fly (upgrade of functionality + db)
  • And of course freeware as much as possible 


I taking this project as study case - so any platforms/languages/methodologies will be taken into account.