Things that you might want to look for on these points.

Hard Disk Size : 60GB>
RAM Size : 1GB >
Processor : Intel Mobile Dual Core if possible / AMD Turion 64.
Graphic Card : Intel (Yes Intel Works only those 945G would be your best choice but you need at least 2GB RAM ) / ATI Cards Radeon or X Series / Nvidia GeForce Series Try those with Turbo Cache.
LCD Screen : 14.1 " - 15.4" if possible The bigger the better.

So there you go, the rest on the not book is just common, such as WiFi and 100/1000 Base LAN.

I'm planing to get the Asus A8J notebook that comes with Nvidia 7300 GFX on it with Turbo Cache.

No offence to all the ATI supporters out there, Nvidia seriously have the advantage with World of Warcraft.

Also I see those people who complain about their game lagging usually have system RAM below 1GB.