There are lots of tutorials about specific aspects of Excel available on the internet. Just Google it. Try a phrase like "the basics of Excel 2007" as a first stab - it does return some "on topic" results.
But probably the fastest way to get into it and get an overall view of what Excel can do, and how to get it done is to pick up a copy of Excel 2007 for Dummies (even Excel 2010 for Dummies wouldn't be bad - but there are a couple of differences in the layouts
of the Ribbons between 2007/2010). The "For Dummies" series of books are generally very good at taking you from a "I know absolutely nothing about the subject" on up the ladder to various aspects of the subject. I personally own several of them on various
topics. It will also end up being an invaluable reference resource to you as time goes on.
Another good book for the beginner would be Microsoft's "Excel 2007 Step by Step". Again, a from the ground up teaching book intended for self-study.
Good luck, and welcome to the wonderful, wacky world of Excel.