In this post there are two different ways to learn how to tie knots. The first is a pictogram of forty different knots by the Boy Scouts Of America which shows a picture of each knot.
With these links you will find a huge amount of different knots and what the knots are mostly used for.It is shared by Survival Magazine. The second link is to a pdf that shows how to make different knots and tells what to use each knot for and it is offered by Scout Resources UK. Between these two resources you should be able to tie just about any knot you would ever need and when to use which one. If you are a survivalist then check out, Every Survivalist Should Know the Trucker Hitch Knot.
Click here to see all 40 different ways to tie rope into knots:
Click here for the PDF of Knots and Their Uses: