Most home routers like this can be configured through your web browser, although initial configuration usually must be done with a cable connection, as the wireless is sometimes off by default or at least set so you can't configure via wireless for security reasons.
The default for most of these is to be set up for DHCP on the Ethernet (LAN) ports. So, just set your network card to obtain the IP information automatically. The router will most likely give it the standard 192.168.1.* and the router itself can is normally 192.168.1.1 (although I've come across some that use 192.168.0.* and 192.168.0.1 for the router).
Once you've got everything hooked up, and you've obtained your IP from the router, simply open up your web browser and go to the address
http://192.168.1.1.
You should be greeted with a login screen. The default is normally something like username: admin with no password, or username: admin; password: admin. Hopefully this information can be found in the manual.
Once in, it shouldn't be to hard to navigate the menus. Most of the settings can be left on the default, and you shouldn't need to worry about things like port forward/filters and such. I'd start by finding the menu for the wireless setup.
First, make sure it is enabled.
Second, change the SSID, in case others in the area have a similar model and left it as the default. For extra security you can disable the SSID broadcast, but then you'll need to remember what it is in order to find your network again because it won't be broadcast as an available one.
Finally, enable some type of security for the network. I'd suggest just using the WEP (Wired Equivalent
Protection Privacy), it isn't the greatest protection, but it is simple and will prevent most from just signing up on your network. It consists of 4 or 5 (if I remember correctly it's 5) double digit groups of numbers. These are in hexadecimal so you can use 0-9 as well as A-F as numbers in each field. Type them in kind of randomly, don't use 12 34 56 67 89, or AA BB CC DD EE FF, that kind of thing. However, remember this number because you'll have to enter it on any computers you want to be able to connect to the wireless network.
This should be all there is too it. Also, it is a good idea to change the username and password for the login to the configuration menus also.