Well to many webhosting clients and webhosting companys, There are always questions about what to do for Cpanel. However many hosts are unable to help with demos and such so, im posting links to free demos and tutorials for Cpanel witch will help you and your clients with troubles. All tutorials posted are created and hosted by the creator, however they all have given you the read the right to use and direct clients to them in need of support. However please do not duplicate them for your own good.

For Demos On The Following Vist - http://www.dayanahost.com/tutorials.cfm:
Cpanel Controls:
Creating a POP email account
Creating a default (catchall) email account
Creating an email account in Outlook Express
Creating an auto-responder
Creating a subdomain
Creating custom error pages
Password protecting a directory
Creating a MySQL database
Managing a MySQL database in phpMyAdmin
Installing FrontPage extensions
Using File Manager
Using Index Manager
Enabling Hotlink Protection
Redirecting a URL
Redirecting mail
Changing your control panel password
Creating an add-on domain
Creating an FTP account
Backing up your site
Using WebMail

Web Hosting Manager:
Managing your hosting packages
Managing your hosting accounts
Managing your bandwidth
Managing your subdomains
Managing your Skeleton Directory
Managing your DNS zones
Managing your suspended accounts
Managing your parked domains
Managing your FrontPage extensions
Modifying your account passwords
Monitoring your server
Troubleshooting email
Setting up a remote access key
Changing your WHM theme