Everything you need regarding Red Hat can be found on their site:
http://www.redhat.com/en
If you want to get certification you need to read and study, a way to start learning is to use google and find Red Hat by yourself, it is quite easy!
Along that line, you should first start and use Linux and become familiar with it, just being certified will not substitute for hands on experience.
Be advised Red Hat requires subscriptions to get support so if you want updates you will need to pay. You may want to look into
CentOS which is free to use and is almost like using Red Hat.
