This is my handbook for data analysis, mining, cleaning, aggregating, R and possibly data science. It has been written during taking the following courses on coursera prepared by Johns Hopkins University.
Why "hidden" data scientest? It is inspired by pioneer hidden scientist.
If you are a developer able to write code in Java or similar language and work with databases, you might find this handbook useful and un-hide your data scientist potential.
Everything in this handbook is meant to be a quick learning material. There is no deep explanation of R language or anything else like that. But there are many examples with minimum information and many external references to study.