Great walk through http://www.trainsignaltraining.com/how-to-setup-iscsi-drive-using-freenas/2009-01-19/
PS. Once the drive shows up in computer management on Server 2008 - it may be offline (with some bogus error about security policy). Right click offline and click online. You will likely also need to right click again and initialize. Then you should be able to right click the drive and partition.
Great video on Server 2008 Quorum http://www.youtube.com/watch?v=j9E1LgLwG88