Recently for a customer I was searching for some best practices documents about Hyper-V.
I came across two articles by Roger Osborne which are both interesting. They both describe the best practices for Hyper-V in the same way.
The first is a list for Hyper-v 2008 R2 and the second is for use with Hyper-V 2012.
I have a customer who is currently implementing XenDesktop 5.6 with Hyper-V 2008 R2 (2012 is not supported with XenDesktop 5.6), but they will eventually migrate to XenDesktop 7 which can be run on (and supported with) Hyper-V 2012.
The best practices are in a clever checklist format, therefor easy to use:
Hyper-V best practices for 2008 R2 SP1 can be found here
Hyper-V best practices for 2012 can be found here