I have been heavily influenced by the writings of Ben Graham. Consequently, I have tended to own a lot of low price-earnings, low price-to-book goo, and often been disappointed with the results - cheap stocks that went on to get even cheaper. It was time for me to consider a better approach: higher quality companies at reasonable prices (or very cheap, if they're available) - the Warren Buffett approach. Everybody, of course, wants to be the next Warren Buffett. He talks extensively about wonderful businesses, but says little about how these things are identified.
This is where this Little Book comes in. It talks about "moats" (which Greenwald refers to as "franchises", or which you or I could call simply "mini-monopolies"), and tries to identify the difference between true moats and false moats (i.e. ones that are currently earning high returns on capital, but whose advantage is likely to be quickly eroded though competition). He also reviews the sectors in which moats are likely to be found (he likes financials quite a lot). He identifies the types of moats (for example, those involving high switching costs to the consumer). He also suggests looking at numbers like ROE (return on equity), ROA (Return On Assets) and ROIC (Return On Invested Capital) as a way of identifying potential investments. So you could, for example, use a stock screener to screen for high ROE as a starting point. He also covers establishing a suitable buy price, and a sell decision.
The book goes a long way to giving practical advice into analysing a situation, and has more substance than a lot of the generic waffle that you hear bandied about Buffett's investing style. This book has certainly been food for thought for me. It can't, of course, turn you into a Buffett superinvestor overnight - much as we'd all like. You still need a qualitative feel for companies that no book can really give you. The good news is that this qualitative understanding is an accretive process that can be obtained by reading lots of accounts and business newspapers/magazines.
I suggest reading this book, together with Intelligent Investor by Ben Graham, and The Little Book That Beats The Market by Joel Greenblatt. You might also want to perform a web search for Li Lu, who has recently been identified officially for the role of Berkshire Hathaway's chief investment officer.