Ubuntu

Actually i took some classes for that as you are already in touch on this basis you can do participate.But one thing i would recommend you that is troubleshooting practice because it is the most troublesome round for getting certification, on the behalf of this i told it's bit tough but not scary.

The topics covered by this exam include:

Code:

Hardware, Device Configuration, and Installation
Linux Filesystem Management
System Initialization and Services
User Administration
Network Configuration
System Administration Tools
RPM, Boot Loaders, and Kickstart
Kernel Services and Configuration
The X Window System
Troubleshooting

Go to Redhat for more information.... May be it helps you.
redhat.com | RHCE Prep Guide

Best of luck
Daya...