Like me you might find implementing Moodle on a LAMP (Linux, Apache, MySQL and PHP) a little tricky and I personally want it on Windows Server, SQL Server and IIS.
A Windows System can scale differently to anything like MySQL and you can manage it in a high availability environment with Microsoft SQL Clustering and Mirroring.
Here is a whitepaper that I have put together on how to installing Moodle 1.9 on Windows Server 2008 x86, PHP5, SQL Server 2008 and IIS.
Get the white paper here: http://learninggateway.net/blogs/ajp/archive/2010/03/29/installing-moodle-on-windows-server-sql-iis.aspx. Special thanks to Julian Ridden who tagged this in his Delicious account.
You also might find this Moodle.org resource handy: http://docs.moodle.org/en/Installing_Moodle