How can I find information that's in my computer quickly. I have a Mac OSX?

Spotlight should be able to do this. Like any search tool the answers you get are only as good as the question you ask there are a couple of sites that may help there are many more sites that also have tips for using Spotlight.
UseingMac.com

Spotlight tips

I agree with cmeeks. Using the spotlight is probably your best option. If you're looking for Apps or frequently used folders, using the Finder is beneficial as well!