The art of lockpicking is used to open locked doors and containers faster and with fewer broken lockpicks

If you are playing a thief type class, you should definitely spend points in the lockpicking tree. If you are not a thief, while lockpicking is not mandatory, it is still useful to spend points here to get access to more powerful and valuable treasures.

Level up lockpicking by picking locks of lock containers. Even failed attempts can increase your lockpick skill slightly.

TRAINERS

Expert Trainer: Majhad (Khajiit Caravan)
Master Trainer: Vex (Riften)

PERKS

Novice Locks
Novice locks are much  easier to pick

Note: Novice lock are pretty easy to pick as is, so getting this skill will make picking those locks almost automatic. You need this skill to unlock the rest of the tree anyway.

Apprentice Locks
Apprentice locks are much easier to pick
Requires: Novice Locks, Lockpicking 25

Note: When a lock is "easier to pick" it means the arc where the lock rotates and opens is slightly wider

Adept Locks
Adept locks are much easier to pick
Requires: Apprentice locks, Lockpicking 50

Expert Locks
Expert locks are much easier to pick
Requires: Adept Locks, Lockpicking 75

Master Locks
Master locks are much easier to pick
Requires: Expert locks, Lockpicking 100

Note: Take all the above 5 perks to allow you to easily open even the toughest locks.

Quick Hands
Able to pick locks without being noticed.
Requires: Apprentice Locks, Lockpicking 40

Note: Useful for lockpicking without being detected

Wax Key
Automatically gives you a copy of a picked lock's key if it has one
Requires: Quick Hands, Lockpicking 50

Note: Lets you re-open any lock you have picked before.

Golden Touch
Find more gold in chests
Requires: Adept Locks, Lockpicking 60

Note: Take this as it will significantly increase the amount of gold you end up with if you loot a lot of chests.

Treasure Hunter
50% greater chance of finding special treasure
Requires: Golden touch, Lockpicking 70

Notes: Get this skill for more chance of finding powerful weapons and armor

Locksmith
Pick starts close to the lock opening position
Requires: Expert Locks, Lockpicking 80

Note: Makes lockpicking even easier by giving you a hint as to where the final position is

Unbreakable
Lockpicks never break
Requires: Locksmith, Lockpicking 100

Note: Take this to never worry about lockpicks breaking again.