SQL Server 2008
I get a lot of questions around SQL Server 2008, it seems like a lot of people have started to look at this product to see what it can do and how to skill up on all new features. The SQL Server TechCenter is a good place to start, here you can find product documentation on how to get started and white papers on everything from Data Warehousing to encryption and how to improve performance. There is also a free E-Book available now from MS Press, download it here
You can of course learn a lot by reading documentation to get facts, but for myself I want to try things out. You can of course install the product in a virtual machine and play around but I would also recommend you to try our Virtual Labs on SQL Server 2008. This gives you a manual that you can download and then do the lab online without installing anything. There is more than 20 available labs around SQL Server 2008. See the full list here: SQL Server 2008 Virtual Labs. If you want to run it yourself you can download a trial here. If you want to watch videos instead there is a lot of SQL Server 2008 videos on TechNet EDGE
I also want to recommend the SQL Server 2008 Compare site where you can look at comparisons between SQL Server 2008 and Oracle, DB2 or MySQL. You find both White Papers and Case Studies around this for all these products. We also have a tool called SQL Server Migration Assistant (SSMA) to help you migrating from Access, Oracle or Sybase. Read more about that and get access to the tool here
All this information and links should keep you busy for a while :-) Good luck!