Companies with at least 500 stockholders and/or $5 million in assets and/or big private debt placements must file disclosure documents with the SEC. Brokers, investment advisers and certain shareholders must make filing too (see "Brokers," "Investment Advisers" and/or "Shareholders").
The rules for making filings are described in the SEC's Edgar Filer's Manual and A Plain English Handbook: How to Create Clear SEC Disclosure Documents.
TO GET FILINGS from the last four years, you can use the SEC's free EDGAR database, or the historical EDGAR database, which goes back to 1994 (but doesn't include the most recent filings). If the free SEC databases are too limited, try SEC Info or a fee-based service such as Knowledge Mosaic, LIVEDGAR, Morningstar Document Research (formerly 10k Wizard), Intelligize, Bloomberg, SECnet, EDGAR Pro or DisclosureNet.
EXHIBITS to filings are available from LIVEDGAR, Morningstar Document Research and Lexis (COMPNY;EDGARP) and most of the other fee-based services, or place an order with Thomson Research Services (formerly Disclosure) by calling 800-249-1440, or contact a competitor.
TO SEARCH FILINGS, you can try the SEC's free Full-Text Search, though that goes back only four years, or the SEC's historical EDGAR database, but that searches only header information. Otherwise, use a fee-based service such as Knowledge Mosaic, Intelligize, Morningstar Document Research, SECnet, LIVEDGAR, EDGAR Pro, Bloomberg or
Lexis (COMPNY;EDGARP or Lexis Precedent Search). You can also use Westlaw, but years ago I found the Westlaw database frustrating and haven't tried it since.
If you need to get a filing that is TOO OLD TO BE ONLINE, you can order the document from the Washington Service Bureau (800-289-1057), ThomsonReuters Custom Research Services (301-545-4930 direct to DC; main number 800-249-1440), GSI Document Retrieval (800-669-1154) or another document retrieval service. Alternatively, you could check with your local public and/or academic business libraries to see if they have historical collections (probably on microform).
Just about all the sources for filings tell you the date of filing. If you pull up a filing using the LIVEDGAR Company Search, you will also see the time of filing in the "Accepted" field. SEC Info has times for Today's Filings (actually the most recent business day - you'll get Friday's on Saturday or Sunday).