How much damage does each tool do?

The damage charts can be located here but I cropped them for you.

Mobs' health is measured in 'hearts', just like the player's. Chickens have 2 hearts; sheep have 4; cows, squids and pigs have 5; spiders/cave spiders have 8; skeletons, creepers, blazes, tamed wolves zombie pigmen, and zombies have 10; Ghasts have only 5 hearts. Wild wolves have 4 hearts. Slimes and magma cubes react differently to damage. Their health depends on their size.

Any tool not listed above (hoe's, shears etc.) will do normal "fist" damage when used.

Critical hits are as following:

In 1.8 or earlier versions, tool damage bonuses are:

• Swords (4 for wooden or golden, +1 for stone, +2 for iron, +3 for diamond)
• Axes (3 for wooden or golden, +1 for stone, +2 for iron, +3 for diamond)
• Pickaxes (2 for wooden or golden, +1 for stone, +2 for iron, +3 for diamond)
• Spades (1 for wooden or golden, +1 for stone, +2 for iron, +3 for diamond)

• Hoes (N/A)

  Note: They also receive +1 from initial attack strength.

  So for a diamond sword you will deal 4 hearts of damage if the hit is not critical.
  Note that critical hits deal +50% more damage than usual ones.

  In 1.9, tools also have a cooldown, which prevents you from hitting too often (even if the cooldown is short; see here for more details.) Also, axes deal +2 damage than previous versions, more than swords, but the cooldown for them is big, and they are damaged 2 durability points per hit, rather than swords. Except for axes, tool damages are the same as in 1.8.