Didier Hilhorst and Dan Rubin of SuperfluousBanter fame have written and released for free (for 7 days) Budget Design: Increase Profit by Improving Process. After 7 days, it'll set you back $9.

All web developers should take a look at it (even if your budget is larger than the US trade deficit), because it's quality stuff from 2 quality web developers (and now, writers).