Quote from HumbleBobby:
The 2 books I would look into are: Trading Risk from Kenneth Grant and Profitability and Systematic Trading by M. Harris.
Also you can follow this link for a quick and simple look into money management: http://financialsaint.com/cms/cms/viewer/page/422
Both books are excellent. Good suggestions. I especially liked Profitability and Systematic Trading because it explains really well the notion of risk of ruin and its relation to consecutive losers using basic math. The author also explains well the differences between various position sizing approaches and their relation to trading timeframes. On page 79 of the book the author presents a practical risk and money management plan that IMO should be closely followed by every trader. This is definitively one of the best books on systematic trading and risk management I have ever read.