Data Mining is as much art as science, and is not yet turn-key. Therefore, all those tips and tricks that one learns from experience (and are not in textbooks) can make or break a data mining project. This blog is intended to be a repository of user experiences in data mining.
If you want help with data mining, there are other sites that provide FAQs and tutorials. The links provide some locations for this. Please limit yourselves to success/failure stories and followup question.