Steps in meiosis

The Eukaryotic cells can be divided by meiosis or mitosis. In humans, mitosis generates new cells for growth and though mutations are the ultimate source of genetic variability, both meiosis and sexual reproduction as well can contribute to the new genetic combinations in offspring.

Question: How do both meiosis and sexual reproduction (that is, fertilization) generate offspring which differ genetically from the parents? Be sure to talk regarding steps in meiosis which raise variability and also the method of fertilization.