Service Provider: http://www.2x.com/managed-service-provider/
Sites: http://www.2x.com/support/ras-documentation/manual/sites-management/
XenServer VDI HowTo: http://kb.parallels.com/en/123191
XenServer VDI HowTo - Old: http://www.2x.com/support/ras-documentation/vdi-agent-technology/preparing-citrix-xenserver/
Universal Printing: http://kb.parallels.com/en/123147
Support, Forums and KB: http://www.parallels.com/products/ras/support/