There's an option for 'automatic account creation', where the username is automatically generated or 'normal registration' where the user can set their own username, password or email address. It's very configurable as to how much, or how little, the user needs to fill out to register. You can even have the username pre-filled with a username that is available, but the user can change it something they may like more.
We use the "Automatic" setting on this site simply because we want users to get in quicker. This isn't much of a 'social' site, it's a sales and support site, so getting where you want to be is more important the customization of your profile.
As for redirection, there is an option to enable the new user or returning user redirection. When enabled, the user will go to the menu item set. If it's disabled, they will remain on the same page they logged in from.
I hope that helps explain, but if you have other questions, just let us know.
Thanks,
Alex
User Names and Passwords
