A question clients often ask is should we register on such and such an online directory ?
We are firm believers in quality over quantity so look at the Directory and see if it somewhere you want your company to appear, also look at the competition are they there if they are then you should probably be there to. Try to avoid registering on every directory going especially if they are not really related in any way to your business or area of business as this could convince Search Engines that incoming links that are not relevant may dilute your message about your business.
If you business relies on geographical coverage say for example you are an Italian Restaurant in Watford then however nice it is for the ego you will want to appear high on regional searches for Italian Restaurants such as in Hertfordshire and here Regional Directories can help your cause, make sure you are registered with all the directories in the area such as Watford and surrounding areas and Hertfordshire.
With a process like this take a methodical approach and gradually build your prescence on the web – Search Engines like to see a growth rather than explosion as this will lead to short term gain but long term damage.