Registration and membership on Tolkien Forums is free and very simple.
To register with Tolkien Forums Click Here. Enter your details (* = required) and then press 'submit'. You will be notified by email of your registration. In that email there is a link which MUST be clicked in order to fully activate your Tolkien Forums account.
When you register with Tolkien Forums the first detail you will need to enter is your chosen username. Try to keep it related to Tolkien/Middle-earth in some way. Make sure you can remember your username, complicated usernames like 'frodo3671a' are going to be difficult to remember. Alternatives could be simply 'frodo' or 'frodo123' or 'frodoabc' etc.