Some of the free courses that caught my interest were:

• Course 4628: What’s New in Microsoft Office Word 2007
• Course 4625: What’s New in Microsoft Office OneNote 2007
• Course 4624: What’s New in Microsoft Office InfoPath 2007
• Clinic 3199: Getting Started with the 2007 Microsoft Office System (Beta)
• Clinic 3369: Getting Started with Microsoft Windows SharePoint Services 3.0 (Beta)
• Clinic 5045: Inside Look at Developing with Microsoft Windows SharePoint Services 3.0
• Clinic 3370: Getting Started with Microsoft Office SharePoint Server 2007 (Beta)
• Course 2913: Creating Your First Microsoft ASP.NET 2.0 Web Application
• Course 2915: Working with ADO.NET 2.0 Within Microsoft ASP.NET 2.0 Plus Access to Online Library

Their learning manager interface is pretty nice. It keeps track of the courses you have registered for, and even your progress inside those courses. You can stop a course, come back to it later, and pick up in the section you left off.

If you use any Microsoft software, and feel like you have room to sharpen up a bit, you might check out the Learning site and see if there are any free courses available that you can register for.