Internet via wlan adapter

I want my Raspberry Pi to connect wirelessly to my wlan router (which has internet access). After that I want to connect my Raspberry Pi via LAN cable to a router. This new router should get internet from the raspberry Pi. So it should look something like this:

Internet_WLAN <-> Wlan-Adapter_on_RaspberryPi <-> LAN_Cable <-> Router

I have an Alfa AWUS036H wlan adapter, which is attached to my Raspberry Pi via USB.
I followed this tutorial to install the alfa driver and connected my Raspberry Pi (wirelessly) to my wlan router: http://omer.me/2012/04/setting-up-wirel ... pberry-pi/

The next step would be to "make a bridge" between wlan0 (which is the alfa wlan adapter) and the ethernet port to the router, so that the router "gets internet".
Can somebody tell me how I can do that? I'm not experienced with bridges so a tutorial would be nice. Thanks.

The second answer on the following page seems apropos:

http://superuser.com/questions/520172/w ... e-in-linux