Yahoo Finance is a one stop destination for information on individual companies and the stock market as a whole.
Morningstar is a great resource for all things stock market. There is a wealth of information for free and even more on the fee-based premium site.
Marketwatch is a good resource for market indices information.
The Motley Fool provides great insights and articles.
dividata is a great source for information regarding dividends.
Investopedia is a great site for definitions, terms, and concept discussions.
StockCharts is an easy to use fee-based charting service.
I use Excel spreadsheets to track monthly price data and create the technical indicators I utilize to identify when dividends are “on sale.” Historical price data can be downloaded from Yahoo Finance directly into Excel.
What Works On Wall Street – James P. O’Shaughnessy
Stocks For The Long Run – Jeremy J. Siegel
The Warren Buffett Portfolio – Robert G. Hagstrom
The Warren Buffett Way – Robert G. Hagstrom
Buffettology – Mary Buffett
Security Analysis – Benjamin Graham & David L. Dodd
Common Stocks and Uncommon Profits – Philip A. Fisher
The Strategic Dividend Investor – Daniel Peris
The Dividend Imperative – Daniel Peris
Get Rich with Dividends – Marc Lichtenfeld
Dividends Still Don’t Lie – Kelley Wright
The Single Best Investment – Lowell Miller
Dividend Growth Machine – Nathan Winklepleck