What is the procedure to realize zero mean and unit variance? The tag on feature scaling says:


  Popular feature scaling types include scaling the data to have zero
  mean and unit variance, and scaling the data between a given minimum
  and maximum value.


Are there any details that help us to generate zero mean and unit variance?
To generate zero mean and unit variance, you are looking at standardization. Where a feature $x$ becomes scaled feature $z$ like this:

$$z = \frac{x - \mu}{\sigma}$$

Where $\mu$ is the mean of that feature and $\sigma$ the standard deviation.