General Questions

I have a D-Link network camera. I want to be able to see it from other computers on different places.

In the instructions it says that I should Open Virtual Server Ports To Enable Remote Image Viewing.

• Select Enabled to enable virtual server settings.
• Select a camera name.
• Enter your camera’s Local IP Address in the Private IP field.
• Select TCP under Protocol Type.
• If you are using the default camera port settings, enter 80 in to the
Public and Private Port section.
• Schedule should be set to Always so that the camera images can be
accessed at any time.
• In the Virtual Servers List, a check mark appearing before the camera
name will indicate that the ports are enabled.
• Click Apply to save your settings. Note: If you are installing multiple
cameras, be sure to open ONE port per additional camera installed:
port 81, 82, etc. for web server.

I have no clue how to do this with m0no0wall. Please help me.

I am guessing that the camera has a USB and Cat 5 or wireless connection.  It sounds like it has some control software that enables you to enter the settings probably via USB.  You then need to enable the "Virtual Server" on the camera and specify a port.  This will be the web server that allows you to connect to it over the network.  I would recommend that you don't use 80 as this is the common port for http and could add a un-necessary risk to opening up your network to the outside world.  Start with port 81.  on monowall, you need to look at the NAT page and add an incoming NAT.  The interface is WAN the protocol is TCP the external port rage is left blank the NAT IP is the IP address of your camera and the local port is the port you configured on the camera, e.g. 81 Give it a description and then check the box to automatically add a rule for it.  This will now pass any requests to your router on port 81 through to the camera.
You might also want to set up a Dynamic DNS account to have a dns name in the external world for your router.