I'd recommend the following books: Financial Statements Step by Step (http://www.amazon.com/Financial-Statements-Step-Step-Underst...)

Financial Intelligence (http://www.amazon.com/Financial-Intelligence-Revised-Edition...)

Financial Intelligence for Entrepreneurs (http://www.amazon.com/Financial-Intelligence-Entrepreneurs-R...)

Another great resource is Financial Intelligence for Entrepreneurs:

http://www.amazon.com/Financial-Intelligence-Entrepreneurs-R...

So far is the only book I know that explains why and not just what.