Electrical and Electronic
The Applegate database is very good for electronics. It is up to date and has web links for most entries. It also has many search criteria, including postcode and town, so that you can restrict your search to companies near you.
Kellysearch is the buyers bible so contains details of manufacturers and suppliers of products and services. It is an electronics products manufacturers and suppliers database with postal addresses and telephone numbers. It has very flexible search criteria including type of industry and geographic location. You can enter the name of the organisation if you know it.