Peter Lynch posted a 29% annual return as head of the Magellan Fund through much of the 1970s and 80s. In his book, One Up On Wall Street, he tells the investor how to generate returns superior to those of Wall Street.
The professional investor has a number of disadvantages relative to the individual investor. Lynch teaches you how to exploit these disadvantages to your advantage. For example, professional investors don't often use the products/services of companies in their portfolios. The individual investor, however, uses a number of products in his leisure/working life that Wall Streeters don't. Investors should be on the lookout for new products that their friends and/or co-workers are using, as a great source of ideas, and in order to have a pulse on product trends in areas in which they know something about.
Of course, sourcing ideas is just the first step. Lynch goes on to discuss what to look for in a potential stock and what to avoid.
Not long ago I also read Lynch's other book, Beating The Street, and I must say I found the books rather similar. The aims of the book are different (one is about how he outperformed, whereas the other is advice on how the amateur can outperform), which does lead to some different discussion, but the themes are generally the same. As such, if you're interested in knowing more about what's in these books, I'll point you to my review of Beating The Street here.