US copyright registration is done through the US Copyright Office. It is not done through the writers’ groups!! Yes, there is at least one writer’s group out there that you can register your work of authorship with, but that’s not copyright registration.
To actually register your copyright, you need to know a few things. First, you need to know what type of work of authorship this is. Is it a written work? A work of the visual arts? A musical work? A movie? Or is it some combination (movies contain music, for example).
Once you’ve got the type of work, you need to know who the author is. Maybe that’s you. Maybe it’s your employer. Maybe it’s someone else.
Then the Copyright Office’s registration bot leads you through a series of questions about the work and about the author … and about the speed with which you want the registration to process. Fair Warning: Unless you have some VERY specific reason, from a cost basis you do NOT want “special handling.” That raises your registration fee from less than $100 to well over $700. Don’t go there unless this work is on the courthouse steps being litigated.
After you’ve answered all of the Copyright Office’s questions, it’s time to pay them and submit your copies of the copyrighted work. They allow certain works to be electronically submitted; for others, you must mail two best copies to them. Yes, they give you a mailing label … which does not include postage. Also, remember to affix … as in staple or glue … the tracking tag to each copy you submit.
Once you ship the works off to the Copyright Office, you sit back and twiddle your thumbs until either you hear from the Office with questions for you or the registration certificate arrives in the mail.
Put your registration certificate in a safe place. You’ll need it if you ever need to enforce your copyright.