Edit emails and messages

Hi There. I just installed Membership and I want to edit the email and the message that happens after a user registers. My whole site is for members only. When they register, they currently get an email that gives them their user name and password, but when they click on the link and try to login, it says taht they are not approved. So, I would like the email to not go out to the user until I have approved them. And I want to change the message that comes on the screen afer they register to say that they will get an email after they have been approved.

Thanks for your help