I am building a new server that needs about 10 separate drives for the software that's being installed. Do I just go into the vm settings and add the additional disks, with their provisioned size, and then map them in Server 2012? I've created 1, and it's showing in Disk Management in Server 2012, but I think I need to initialize the disk, correct?
In Windows-terms "disk initialization" just translates to the process of writing a MBR/GPT label with an empty partition table on an otherwise completely empty block storage device. So yes, you have to do that regardless of whether it's backed by a virtual disk or a physical storage device on a physical server if you want to create and format partitions on the disk.
You can initialize it just in disk management MMC as well and you need to do that for every separate disk.