Welcome!
1.) Use Enthusiast Firmware for your Router. Consider, there is a difference between WL500gP V1 and V2.
The firmware is up to date and stable.
2.) Use Wengis HowTo, it is still valid.
In case you want to have a very modern system, you can install "entware" instead of "optware"
The Optware part is included in wengi's howto.
Entware is here: http://code.google.com/p/wl500g-repo/
Just ask when you are in need.
HTH Newbiefan