The Standard & Poor's (www.standardandpoors.com) company does many things, including (a) rate other companies' debt, (b) compile equity indexes, such as the S&P 500 and (c) publish many useful company-related books and serials, including the Standard & Poor's Stock Guide, the Standard & Poor's Industry Surveys and the 500 Guide.
The "Fixed Income" section of the S&P Web site posts recent S&P debt ratings, tells you who to contact for more information and explains the S&P rating system, among other things. The Indices section of the Web site provides information on the various S&P Indexes.
For other questions, call S&P at 800-221-5277.