If you have create CNAME record for your domain in google apps then you can access your mail by clicking the following link:
http://mail.<domainname.com>
If you are not able to see your login page by clicking above link then please click on following link:
http://mail.google.com/a/<domainname.com> (This is the temporary link to access mails)
To Create New User for your Google apps account click on "manage this domain" link and you will get another window, click on create new user link to create new user.
You can directly click on the following link to create users:
https://www.google.com/a/cpanel/<domainname.com>/Dashboard
** Replace <domainname.com> with your actual domain name.
** If you will delete any mail account then you will not able to create the same mail-account for another 6 days.
** There are few settings which are not undoable.
