There are many introductory linux books and documents. If you will be focussing on RedHat products, you should look for RedHat books. There are primers and study guides for their courses as well as the indispensible Redhat Linux 5 Bible.
Note: the official Redhat courses are usually well tailored for different starting skills. Talk to the course people and they will let you know what they can do for you.
Since you'll be doing admin stuff, you'll look more professional if you put a space after each punctuation mark and use upper case for your personal pronoun.