BP for a whole platform upgrade

Hi,

I'm running a vSphere 1.5 platform with autodeploy on a series of ESXi Cisco UCS and nexus1000v, vCloud Director 1.5 and its relative Chargeback, vShield Manager and vCOPS.

I'd like to upgrade the whole platform to 5.1 (hopefully to 5.5).

Of course I'm not asking these BPs here simply with a post, but some hint for resources to carry out this quite complex operation, maybe some links or guides (digital or paper).

What I'm looking for is, a.e., the correct or preferable sequence to perform these upgrades, advices on VMs sizing and so on.

Could you please help me?

Thanks a lot.

Raffaello