This is a direct quote off their website. A copyright registration is effective on the date the Copyright Office receives all the required elements in acceptable form, regardless of how long it then takes to process the application and mail the certificate of registration. This site has a lot of overwhelming information I found, so read carefully. It gives you a list of the types, the forms to download and the fees. It's pretty detailed.
Fees vary for duplications, number of years etc.
A webring is a group of websites who all have something in common in some way and form a link. You do not have to have a website to check the webrings. Carefully check each webring out for the number of sites in each ring. So out of 45 webrings, one ring might have 101 sites while another might have 20 sites. To see the site members in a webring, click LIST after it.