These codes can be helpful when you want to retrieve statistical information produced by the Census as well as search in certain databases.
SIC Code: 5731
Radio, Television, and Consumer Electronics Stores (except auto radios)
SIC Code: 4812
The links below will help you find other relevant codes you may want to identify. You can also find NAICS and SIC codes by looking at the industry information for a company in a database like Mergent Intellect.
You can use NAICS and SIC codes to find Industry reports from First Research.