Sign up page is very straight forward and also a very fast process. Most of the Fields are simple, Name, Email, Phone, Company but sometimes agents ask about the 'Account Name' portion. The Account Name is the actual 'Sub-Domain', eventual login page as well as how we keep your account unique and separate. Do not include spaces or non-alphabet characters in the Account Name. We also recommend keeping it fairly short.
Short answer is that you can use your name, company name or anything you want in this field. Once chosen, you will always log into 'http://whateveryouputinhere.radiusbob.com'
Also, make sure you set your own time zone. It's a step that a lot of people forget to do for some reason!
We included a sample image for reference: