Setting SQL servers for SharePoint 2013

Hi team,

We rae planning to Scale Sharepoint 2013 at our enetrprise level. We need to know the SQL setup requirements , pros and cons of going physical vs virtual server and best approach

I also had in mind of splitting content and service appluication DB's into seperate instance and if its a preffered method. ANy links will really helpful as we are sharePoint guys.

Thanks Basva