What you need
Your Mac, Mac OS X 10.x, VNC server (OSXvnc) on the remote Mac, VNC client (for example, Chicken of the VNC, or VNCDimension) on your Mac.
Potential problems
Moving chunks of changed screen image over your network takes up a lot of bandwidth. Stock 1000- and 100Base-T networks should have ample bandwidth, and AirPort is normally acceptable, although you don't want too many other VNC connections running at the same time. Once you try to reach out over the Internet, even wideband connections can prove restrictive. Tweak screen depths to get the best performance. Although VNC is now quite robust, not all computer systems are as reliable as that for OS X, and you may find clients or servers throwing errors. Use normal platform-specific tricks to help improve stability, for example, disable non-essential extensions in Mac OS 8/9.
Further info
The VNC home page is at www.uk.research.att.com/vnc/. OSXvnc is at www.redstonesoftware.com/vnc.html. Chicken of the VNC is at sourceforge.net/projects/cotvnc/.
Checklist
Check network settings (including IP address) on each computer.
Ping between the two to verify connection.
Ensure port 5901 is not blocked by a firewall.
Start VNC server on the remote computer, assigning a password if needed.
Start VNC client on controller.
Monitor processor and network performance to tune VNC settings.
Click 'Next Page' below for the step-by-step guide...Using VNC for remote control