Vmware released 2 new technical paper on 06/07/2011 which related to ESXI operations and migrations. You can find official download link below;
Migrating to Vmware ESXI
– http://www.vmware.com/files/pdf/VMware-ESXi-41-Migration-Guide-TWP.pdf
Vmware ESXI 4.1 Operations Guide
– http://www.vmware.com/files/pdf/VMware-ESXi-41-Operations-Guide-TWP.pdf