Equivalent of disabling services in Windows to lessen CPU/RAM usage for OS X?
OS X doesn't come with a bunch of unneeded services loaded in the background taking up resources. Most OSes are not as bloated as Windows. There really isn't anything to disable, unless you enabled something that you no longer need. OS X is pretty conservative with what it enables by default, and it often will enable things automatically as needed, and keep them disabled when not.