[ I'm copying idologic_aw's format in hopes to make this a bit easier to follow/fit in with others. ]
1. This step is straightforward - just go directly to http://registerfly.com
Logging into your account
2. On the yellow bar spanning the upper half of the page, there is a LOGON
link. Click it to sign in to, or create your account.
3. Enter your User Name and Password, and select to remember it if you wish. I would advise you to be careful when selecting to have your password remembered -- if someone accesses your account, changes your whois, and takes the domain, your only proof against them is a log [ Reports > Login Report ] that RegisterFly keeps in its admin panel.
Choosing a domain
4. Now inside your account, just click whichever domain you want to setup a nameserver for.
5. Under the DNS Management
area on the main page, select Register/Edit/Delete nameservers for this domain
Creating the first nameserver
6. The first area of this page isn't what you're interested in, so avert your eyes downward toward Register a Name Server:
7. In the first input box, put the third-level domain name to use on your nameserver. This is generally 'ns' or 'ns1'.
8. The dropdown box next to this will let you change to a different domain if you suddenly change your mind about which one you're creating the nameserver for.
9. In the next input box, add your IP address that you will be using for your primary nameserver.
10. Click Submit:
Creating the second nameserver
11. To create additional nameservers, repeat steps 7 through 10. It is generally recommended to have at least
12. You've now created your very own nameservers! Now wait up to 72 hours for them to fully propogate, and you can then begin using them!