The depth of information provided varies in each source but most include history, competitors, basic financials, as well as basic directory information. MarketLine Company Profiles (from Business Source Premier) is the best place to start for US companies.
MarketLine, a Datamonitor company, is a business information company covering the automotive, consumer, energy, financial services, healthcare and technology sectors. Covers major companies in those industries. Most companies will have a SWOT analysis included in the profile. CSUS Authentication Required