Hunters deals mostly physical damage by shooting arrows and bullets in World of Warcraft. It means it is a ranged, physical DPS pet class. Hunters use mana to finish their special abilities. Hunter still can do pretty significant damage without mana, if they have a fairly powerful autoshot and their pets deal damage. They also can regenerate mana with a variety of talents. Hunters have three specs: Marksmanship, Beast Mastery and Survival. Marksman is the standard raiding and PvE spec and tends to deal the most damage. Beast Mastery is perfect for leveling up and it is the best solo-play spec for a Hunter. Survival is a desirable and powerful PvP partner when Explosive Shot deals ridiculous amounts of magic damage.
Hunters weapon is the most valuable piece of equipment for the hunter. If the DPS is higher, the weapon will be better. Additionally, Agility is the best stat for hunters. If you can add it, you can do very well in the game. Depending on the quality of your gear, you will also want to get some armor penetration. It is worth 1400 armor penetration when the cap at 80. Therefore, if you are close to the cap, you can add some gems to grab more armor penetration than usually. Otherwise, go for Agility.
Wolf is the best Hunter pet for PvE 5-mans and raiding. Because it has a buff that can increase group members damage, the Wolf pet is highly desirable for players. In the past, there is no doubt that Scorpid is the best Hunter PvP pet. However, Blizzard decides to cancel the Scorpids ability, so there is no pet can be the best hunter PvP pet now. If you are a Beast Mastery hunter, you can choose the Core Hound to help you cast speed. If you are a Survival and Marks hunter, you can choose the Crab and Spider because they can root the enemy for 4 second.