Now that you have your site running, you want others to be able to signup as a member of your site! This is done through a file that ships with Nucleus called createaccount.html and is located in your root part of your site at:
http://www.yoursite.com/createaccount.html
This simple html document has the form required for a member to signup. It is important to remember though, that membership cannot occur unless you turn this option on in your 'global settings' of your nucleus admin screen.
If you would like the account creation page to blend into your site, you can place your site style html around the form that is in that file.
If you would like to place a link on your site to the registration page, most people would use something like the following:
<a href="http://www.yoursite.com/createaccount.html">Register Now!</a>
This process is the basis for other plugins that deal with the registration process such as NP_NewMemberBlog and NP_AutoJoinBlog.
If you have anything that you would like to add to this document, please feel free to share your tips!
(Note: this is also discussed in the Nucleus FAQ)