Clients want articles written on all type of topics, some of these we have hardly any knowledge about. Thorough research in such cases is extremely important in order to write content that you feel happy to send of to your client.
However I am interested to know how you guys go about researching your assignments?
Personally I use Google to seek out authority type websites and see what the general info being given is. Additionally for opinion based information I like to browse around in niche related forums and Yahoo answers. Having said that I am very selective about which sources I actually value, for example I would never consider anything from a thing MFA site.
I am also trying to integrate ezines into my process.