The book, The Intelligent Portfolio: Practical Wisdom on Personal Investing from Financial Engines by Christopher L. Jones, is a very comprehensive book which covers risk versus rewards, past performance versus future expected returns, market timing versus long term investing, and investing in individual stocks versus investing in mutual funds. He also discusses diversification, fees and expenses, and the tax consequences of investing. All of his recommendations are backed up with extensive research and presented in an easy-to-understand manner. The following is an excerpt from his book about retirement investing: An Unnecessary Gamble The Biggest Mistake in Retirement Investing By Christopher L. Jones Author of The Intelligent Portfolio: Practical Wisdom on Personal Investing from Financial Engines One of the most common mistakes made in the retirement investing world, particularly among 401(k) participants, is over-concentration in an employer's stock. In an analysis of more ...