Need help with Graphics settings

I know how to access the video option and how to change the settings, but I have no idea what the max settings are nor what the recommended settings is for my computer. I just don't understand all the technical stuff.

I have a Pentium 4, 2.00Ghz, 756mb ram, and a Geforce FX 5500 vid card.

I play on Bartz.

In the NPC and terrain settings start with normal and lower it as needed till you feel it's right. Thats about what i would recommended