For those that have not heard about the "Azure" platform, Windows Azure is a cloud based operating system that offers software as services - .NET Services, Live Services and SQL Azure.
SQL Azure, formerly SDS - SQL Data Services, is a cloud based version of on-premise SQL Server, albeit with a few limitations. The benefits are enterprise level availability, scalability and built-in disaster recovery.
Sign up for your copy of CTP1 of SQL Azure here: https://connect.microsoft.com/Survey/NominationSurvey.aspx?SurveyID=5719&ProgramID=2089&SiteID=547
MSDN Documentationon SQL Azure: http://msdn.microsoft.com/en-us/library/ee336279.aspx
Zach Owens, who is a Microsoft Technical Evangelist has blogged about SQL Azure extensively. Check them out here: http://english.zachskylesowens.net/. He has also published a Windows Azure training kit with demo on SQL Azure. You can get that here: http://www.microsoft.com/downloads/details.aspx?FamilyID=413E88F8-5966-4A83-B309-53B7B77EDF78&displaylang=en
Feel free to post any questions you may have on SQL Azure and I will try to answer as best as I can.