Setting up a Search Directory

[caravan]

I work for an advertising and internet agency. Recently we've been thinking about setting up a small regional business directory and was wondering what experiences other people have had who've set one up themselves. What has driven you to start a search directory? What are the benefits to be had and pit falls to avoided? As a user of a directory what do you look for and what are your pet hates?

[Webnauts]

I am looking for high quality web sites, with high quality information.