As far as I know, all household routers have a web interface. This means the type of computer you have doesn't matter when it comes to port forwarding.
To get to your router administration page, type your routers IPV4 address into your favorite web browser.
If you don't know the IP address of your router, open up command prompt and type ipconfig, somewhere in that stream of information there should be a "default gateway" or "local gateway", that is generally your router's IP.
You will then be prompted for a username and password, there is various lists of default ones hanging about on the internet, however if these have been changed you will need to contact the people who set up your router (parents?).
The easier way of doing things I would say is enabling UPnP, this means you do not need to port forward, and avoids having to re-forward for computer changes; each router will enable this differently but usually it is under the "advanced" tab as MillCzarr said. (Note, if your router randomizes UDP ports, this will not work. Some routers also do not support UPnP)
Other than that, follow the tutorial on
www.portforward.com for your router.
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