I am new to Machine Learning / Data Science. As I searched for more resources to learn ML – the concept, tools, I found these interesting resources.
Complete Machine learning overview : Coursera Machine Learning by Andrew Ng. This is the best place to start learning it from the scratch
Complete Data Science : Data Science from Harvard .
As the name states, the difference between the 2 courses is that the first course is more oriented towards different algorithms for learning from the data, the second course is more oriented towards data collection, data pre-processing and understanding the data.
There are a variety of tools/languages that can be used. I have tried Octave, R, Weka, Python, Matlab, Julia. R is one of the widely used in the industry each has its own advantages/disadvantages. Finally I chose to use python since I am more comfortable to python language. (I have tried Octave, R, Weka, Python).
Kaggle is an active community for machine learning. you get lot of data sets with which you learn as well as compete with other kagglers. Start trying out the competitions that are posted in there