Take an end-user position
Have you wondered what the self-service support portal and the ticket-interface looks like for a regular end-user. See for yourself. Choose MANAGE / Users and create an end-user. Select that user and click either "Assume" in the list view, or "Temporarily login as Username" on the profile-page. Now you are that user and you see everything from that user's perspective. When done, simply click "revert identity" in the top-right corner.
You can create a new ticket by hitting Alt+N (Ctrl+N on Mac). It opens the New ticket page in the current window. Alt+M (Ctrl+M on Mac) opens the same page in a new window/tab. Handy.
First impressions last
Don't confuse your end-users more than necessary. Personalize the content of the sign-up page and the verification e-mail, explaining what this new service is all about. Go to ACCOUNT / User population. And add a couple of welcoming notices to the blog too.
Brand your e-mails
Now you have the option to get your message out even stronger. Brand your e-mails with your own colors, design and logo. Go to ACCOUNT / Mail and domains and exploit your HTML skills (only available for Medium plans and up). Don't forget that e-mail address domain mapping is available (all plans) so that you don't need to use the firstname.lastname@example.org address but can use an address in your own domain. XL plan subscribers can also map the account address (accountname.zendesk.com) to a local domain e.g. support.companyname.com.