I assume my my MAC is sleeping if I try and connect with VNC is hangs. If I happen to be at the MAC console I can move the mouse or keyboard and then the VNC works. Is there a way to trigger a wake up or disable sleeping from the console?
Sounds like you need to enable WOL (Wakeup On Lan) in OSX, see the following for a detailed explanation of what's involved and how to do it.
http://lifehacker.com/348197/access-your-computer-anytime-and-save-energy-with-wake+on+lan