The Windsor Knot
The Windsor Knot is wide and triangular, use with wide spread shirt collars.
How to tie a Windor Knot directions can be found here:
The Half Windsor Knot
The Half Windsor Knot is a medium symmetrical triangle, use with standard shirt collars.
How to tie a Half Windsor Knot directions can be found here:
The Four In Hand Knot
The Four In Hand Knot is long and straight, use with a standard shirt collar.
How to tie a Four in Hand Knot directions can be found here:
The Bow Tie
How to tie a Bow Tie directions can be found here:
The Pratt Knot (also known as the Shelby Knot)
The Pratt or Shelby Knot is fairly wide, yet not as wide as the Windsor Knot.
How to tie the Pratt Knot directions can be found here: