As a newbie, I am quite confused how open source software is can/be licensed. I know of licenses like GNU public, Apache, and others.
What is the procedure to license a open source software by developer? What considerations should be made? What choices do I have?
As the developer you are free to license your software (provided you aren’t developing the software for someone else) in whatever way you wish. You have all the choice in the world and you should choose a license that meets your needs. Beyond that, any advice is rhetoric.