Not mine - but I came across this illustrated tutorial. Here is a step by step process on how to register your copyrighted images with the US Copyright Office. A "related" collection of images (could be a 1,000 images) is $35 for online registration. You don't need to be a US citizen or resident - it just provides you additional protections within the US.
... also, I came across this B&H youtube video of the process - its over an hour long... Well actually its a bit more than just on the registration process - its an entire overview of the copyright law, and everything associated with it. The whole enchilada.