Start here, by evaluating how many queries you can give a full and accurate response.
Read thoroughly Scott Mueller's book on upgrading and repairing Computers, 18th editiion, then get your self good books on Office 2007 and 2003, and memorize them. Look at the top 20 book list at Amazon.Com and be able to answer 70 percent of the questions they raise.
Be sure the working people in your company will support a decision to select you by being a nice person and a terrific listener.
Read the posts at all the other tech support sites.
Read the support sites for every computer and printer your company owns... All the explanations that come with the driver downloads, particularly Chipsets, BIOS, and Video graphics.
When you no longer feel like you need to post a question such as your "Looking for Info" then you are ready.