IDG Answers is a community of experts who are passionate about technology. Ask a question or answer one below.
Microsoft offers a number of free tutorials on their site for various Microsoft Office products. And it's hard to beat FREE when you're looking at the price.
And of course you won't want to miss out on free YouTube video tutorials.
Online tutorials have advanced quite a lot since the early days, when it was little more than just text and a couple static screenshots. Most of them now are highly interactive, include course tracking features for management, and some even have links to live groups of other students and/or instructors. Some of the products like Brainstorm are great for as-needed learning since they don't try to teach you everything at once--when you need to learn how to use a particular feature, you can go right to that specific bit of information without having to take a whole lesson.