Simply put, silk screening is a term used in North America to describe the process of printing an image by forcing ink through a fine mesh screen which, in earlier days, used to be made of silk, hence the term. Non-printing areas are masked, preventing the passage of the ink (think of the way a 'stencil' works).
Nowadays with the mesh being made of synthetic fibre, you will find that the term is now called screen printing. However, both can be used. I merely offer the other term to assist you with your research.
While having a go on your own is great, I would still recommend you do some sort of short course should you wish to go forward in earnest. While the information in here is fabulous, it's not always correct and with some of the materials used, in the interests of health and safety (as well as producing good work as opposed to mediocre), it's a wise move to ensure you learn from a reliable source.