How can I find information on consulting firms in the U.S?
Look at the following:
Plunkett's, click on the Consulting Research Center and then click on Company Profiles. At the bottom of the screen, under Business Activities, click on the type of business activity you want and include other criteria as needed.
Company Dossier via Lexis-Nexis and click Create a company list. Type in 54161 into the NAICS code box, and limit by other criteria.
Kennedy Information Consulting Central. A major resource for the consulting industry - some of the information is free.