HOW TO: Upgrade VMware ESXi 5.5 to ESXi 6.0 in 5 easy steps

https://www.experts-exchange.com/articles/18819/HOW-TO-Upgrade-VMware-ESXi-5-5-to-ESXi-6-0-in-5-easy-steps.html

Configure FreeNAS iSCSI and VMWare ESXi (w/AUDIO!)

This is a very useful video that describes how to configure FreeNAS iSCSI as a data store for ESXi. The credits go to mrholverson

A copy of this video is available here