Archery: Archery represents the skill and training needed to wield a bow effectively in combat. The greater your skill, the more deadly your shots. Your Archery skill improves when you damage enemies with a bow and arrows, with the amount of increase based on the damage that you do (minus any enchantments). Of course, only shots that hit their mark will count.
Block: Block is the art of deflecting an enemy's blows with your shield or weapon. Your Block skill reduces the damage you take and the amount you stagger when you block an attack. Your skill increases when you successfully block damage (based on the damage of the blow before it was blocked), or when you successfully bash an enemy with a weapon or shield.
Note that parries with One- or Two-handed weapons are also improved by your Block skill and many Block Perks- you don't have to be using a shield to benefit from this skill. But remember if you have a second weapon or spell equipped in your left hand, you can't block at all.
In the Block constellation, the left arc offers shield-specific damage reduction perks, while the right arc focuses on bash and power bash perks that work with both shield and weapon blocks.
Heavy Armor:Heavy Armor allows you to make more effective use of Iron, Steel, Dwarven, Orcish, Ebony, Dragonplate, and Daedric armors. Heavy Armor offers excellent protection, though its weight will slow you down and reduce the amount of gear you can carry. High-end sets of Heavy Armor are especially rare, so you may wish to consider Smithing so you can craft your own when the time comes.
Your Heavy Armor skill increases when you take damage while wearing heavy armor, based on the damage of the incoming blow. If you're wearing more than one kind of armor, the incoming damage is divided up among the pieces before being used to calculate skill uses. So, the more Heavy Armor you're wearing, the more damage will be assigned to it, and the faster this Skill will increase.
The Heavy Armor constellation has two main themes: The left arc focuses on unusual perks, or those useful in specific situations, while the right arc emphasizes statiscally-powerful perks for heavy armor purists.
One-Handed:The One-Handed Skill governs the use of weapons like the sword, war axe, mace, and dagger. Those trained in this skill deliver more deadly blows. To improve this skill, you must damage enemies with a One-Handed weapon. The skill improves based on the amount of damage you do (minus any enchantments), not the number of swings you take, so while it might take ten hits to kill a bandit with a dagger, you will get the same skill increase for killing him in three with a mace.
A number of perks in the One-Handed constellation improve a specific type of One-Handed weapon. If you generally use the best weapon you can find (no matter what type it is), it's wiser to invest you perks elsewhere: better to have a bonus you can rely on than one you only see occasionally.
Smithing: Smithing is the art of creating and improving weapons and armor. Smithing workstations Include a Blacksmith Forge, Grindstone (for weapons), and Workbench (for armor). Any improvements made at any of these stations count towards your Smithing skill, with the amount of increase based on the value of the item you craft or improve. To increase this skill as quickly as possible, forge your own items and then improve them. You can make Hide and Iron items without taking any perks. You can Improve any item without taking any perks. However, you need perks to create any advanced items, such as Dwarven or Ebony weapons and armor.
Mining, Smelting, and Tanning provid raw materials for smithing, although they do not count towards this skill. Smithing synergizes well with Enchanting, since it guarantees you a ready supply of items to enchant.
Two-Handed: The Two-Handed Skill governs the use of Large weapons such as greatswords, battle axes, and warhammers. Those trained in this skill deliver more Lethal and powerful blows. To improve this skill, Damage enemies with a Two-Handed weapon. The Skill improves based on the amount of damage you do (minus any enchantments), not the number of swings you take, so you get the same increase regardless of how many it takes to fell your foe.
A number of perks in the Two-Handed constellation improve a specific type of Two-Handed weapon. If you generally use the best weapon you can find (no matter what type it is), it's wiser to invest your perks elsewhere: Better to have a bonus you can rely on than one you only see occasionally.
Alchemy: Alchemy allows potent potions and deadly poisons. Their effects are determined by the ingredients you use, but their potency is based on your Alchemy skill. Your skill increases when you discover a new ingredient effect or successfully craft a potion (based on the value of the potion). It also increases slightly if you attempt to craft a potion but fail- while you may lose the ingredients, the experiment isnn't a total loss.
Light Armor: Light Armor allows you to make more effective use of Hide, Leather, Elven, Glass, and Dragonscale armor. Light Armor offers a good balance between weight, protection, and mobility, and is recommended for stealthy characters or those with other forms of protection (such as a good shield or the occasional ward) to supplement their defenses.
Your Light Armor skill increases when you take damage while wearing light armor, based on the damage of the incoming blow. If you're wearing more than one kind of armor, the incoming damage is divided up among the pieces before being used to calculate skill uses, so wearing more light armor will allow this skill to develop faster.
Lockpicking: Lockpicking allows you to open locked doors and containers faster, more easily, and with fewer broken lockpicks. This skill increases when you pick the lock on a door, container or trap trigger hinge, based on the difficulty of the lock. It also increases (slightly) if you break a pick, so if you try picking a difficult lock and fail, it isn't a total loss.
The Novice, Apprentice, Adept, Expert and Master Locks Perks decrease the difficulty of picking locks of the corresponding locks of the corresponding level. This helps save on lockpicks (and frustration), but depending on your Lockpicking skill and your own personal skill at Lockpicking, you may not find them necessary.
Pickpocket: Pickpocket is the stealthy art of lifting gold and other valuables from an unsuspecting target. This skill increases whenever you successfully steal an item, based on the value of the item. Fail to pickpocket something, and you don't receive credit for the attempt. Of course, that's probably the least of your worries at that point...!
The highest-level Pickpocket Perks, Misdirection and Perfect Touch, allow you to steal equipped weapons and armor off of a creature. An excellent trick for a stealthy assassin, there are few more satisfying ways to take down a difficult foe than to strip them down to their underwear before stabbing them in the back...
Sneak: Sneak is the art of moving unseen and unheard. This skill improves when you sneak past someone, or perform a successful sneak attack. You don't get credit for sneaking in an empty hallway, or for just standing around- you must be sneaking (crouched) near someone who can detect you. Avoiding detection is also critical: the moment you are spotted, your sneak attempt has failed, and you can no longer perform a sneak attack (until you hide again)
Speech: Speech allows you to haggle, bribe, persuade and intimidate others to do as you ask. The higher your Speech skill, the better the prices you get when buying or selling items, and the greater your odds of success at dialouge challenges. Your Speech skill doesn't require any special effort to raise: it increases naturally when you sell items to a merchant (based on the value of the item), or when you succeed at a Persuade or Intimidate challenge (based on it's difficulty).