discovering Macs on an IP network

I'm responsible for managing security on the windows and OSX in use here at my company. Many of the people would like to be able to use Macs, etc and have been requesting them.

This is a medical institution in Massachusetts and as such we have some fairly stringent regulatory requirements as well as the moral and ethical requirements for protecting people's medical IDs.

One of the issues is discovering macs on the network. A windows box is fairly simple to identify by the services it is running. As a newbie to Macs (I do remember a time when Macs were little white towers with a neat tiny black and white screen and had a 3.5 inch floppy), I would like to know what is the best way to identify Macs on my network so i can ensure they have the proper security on them.

What can I watch for on the network (IP, of course) that can separate the Macs from the Windows.

Are you talking about BYOD computers?

I assume there is a DHCP server that you are managing?
You should be able to gather plenty of info there as to what devices are Apple.
Hardware Address (MAC Address) Lookup :: Search by hardware address

What type of discovery are you looking obtain.

I work with several health providers in MA and am aware of HIPAA and other regulations.

Are you trying to secure your data, or just identify what nodes are Mac or PC?