Knot work

Tenderfoot

Reef knot - A common and well known knot used for joining two ropes.
Granny knot - A surprisingly common poor knot which slips easily.
Sheet Bend - Used for joining two ropes of very different diameter, or a rope to a hook.
Figure of eight - Used as a stop knot, turned in the end of a sheet.
Clove Hitch - Useful as the start of a lashing or as a temporary mooring.
Sheep shank - Used to temporarily shorten a rope.
Round turn and two half hitches - Similar to a clove hitch but less likely to slip.
Bowline - A very useful and common knot which forms a loop that can not slip.

Pathfinder

Coil and hank - how to organise rope when you have finished with it
Rethreaded figure of eight - Useful for attaching ropes around large anchor points
Fireman’s Chair - Used to manoevre a potentially unconscious person on a rope.
Rolling Hitch - Used to attach a line to a stave or another rope.
Timber Hitch - Useful when hoisting or dragging a piece of timber.
Square Lashing - Useful for making rafts where two staves meet at right-angles.
Sheer Lashing - Useful for joining two staves in line eg for a makeshift flagpole.

Scout

Common whipping - can be made anywhere in a length of rope, often to secure an eye splice.
Eye splice - Used to make a permanent 'eye' hole in the rope
Short splice - Used to join two identical sized pieces of rope permanently
Back splice
Sail makers whipping - Often used to prevent the ends of a rope from fraying.
Diagonal Lashing
Figure of Eight Lashing

A guide to starting knots is also available here