Free Study Materials
Red Hat Exam Prep Guides: These prep guides are nothing more than a complete list of all the things you're required to know when you appear for the certification exam. While it's not study material, you need to know what you have to study. And what better way than Red Hat's own website? Once you know what you're supposed to study, you can simply start trying out labs of each objective. For example, if one of the objectives of the RHCE exam is to configure an FTP server, what better way to study than by setting up an FTP server yourself? The following are some of the ways in which you can study for the objectives.
Man Pages: You might think I'm joking, but man pages are the most useful way to learn Linux. And since the Red Hat exams are practical exams, you need to have a firm grasp over the command line in Linux. Reading man pages can be a daunting task at first, but they're generally the best documents available for that particular tool. Reading a man page in Linux is as easy as typing "man command" in the command line, where "command" is replaced with any command you want to learn, like "man fdisk". If you don't have a Linux environment setup yet, you can browse online for these man pages by searching for them in Google.
Google: Again, this is probably the most popular, but despised answer for studying something. But with a good grasp over Google, you can find just about anything you need. In our case, we can simply search for "configuring rhel ftp server" and we'll find hundreds of guides teaching us how to do it.
Forums/Newsgroups: Talking to people who're experts in Linux or have given the Red Hat exams are one of the best ways to find out more about the subject and clarify your doubts. While I'm not going to recommend a single forum or newsgroup where you will get the best answers, almost all large Linux forums like LinuxQuestions and LinuxForums and Usenet newsgroups will have a separate section for Red Hat Enterprise Linux. You can register at these forums and ask your questions. Since these forums are frequented by people who actually work as systems administrators, systems engineers and so forth, you can be assured that you're getting correct answers. There are also many forums dedicated to helping students pass their certification exams. Just search on Google for "Linux forums" and you'll be on your way.
Chat Rooms: Again, nothing like person-to-person chat to clarify doubts or get questions answered. Almost all of the chat rooms dedicated to Linux are hosted on the Freenode network. To join, download an IRC (Internet Relay Chat) client like mIRC or X-Chat, install it, and then connect to the Freenode network. Almost all popular IRC clients have bookmarked Freenode so it should be as easy as selecting Freenode from the networks list and connecting to it. Once connected, make your way to a channel like #rhel (command: "/join #rhel" in the IRC client) where you can ask your questions.