Data Science is a domain that is associated with data cleansing, preparation, and analysis. First, you need to have a strong foundation in Mathematics, Statistical Analysis, Machine Learning, Data Visualization. You can refer to the following video that comprehensively covers all the concepts of data mining, followed by a case study using the R programming language. Once you are done with the concepts of data mining, you can apply those skills practically on some data-sets. When you think you are good with the core concepts, you can go ahead and start competing on Kaggle. If you are a beginner and want to know more about Python for Data Science then do refer the following video tutorial:
On the other hand, if you want to learn R programming language then do refer the following video tutorial:
You can get a hands-on project by referring to Data Scientist which will teach you Data Science from scratch to advance.
And if you are more into videos then do check out the following video tutorial which will help you in mastering in the field of Data Science:
If you want a detailed explanation of Data Science then do check out Data Science tutorial which will help you in understanding Data Science.