Agility increases one’s armor, dodge chance, ranged attack power, and ability to crit with all weapons. I have been unable to confirm or deny whether this affects wands (everyone instantly calls you an idiot or a troll if you ask these kinds of questions). It is probably safe to assume that, as intended, priests do not want to prioritize Agility. However, it isn’t a totally useless stat, as armor and dodge chance are beneficial for leveling.
A priest’s gear, despite what many seem to believe, makes a rather significant impact on their ability to level efficiently. Of course, better gear is always nice to have, but what is important is understanding why certain gear is better, and knowing what stats to look for on gear. It’s impossible to accurately calculate the value of each stat for leveling, but understanding what each stat does can help one make better decisions when choosing what gear to use.

Most priests opt to play as holy or discipline, but shadow is just as important as the other two specializations. Shadow priests have Shadow Weaving, which boosts all shadow damage done by 15%. This definitely helps the shadow priest, but it also helps warlocks as a much of their damage is shadow-based. Raids are certain to have multiple warlocks, so this makes Shadow Weaving, and therefore a shadow priest, an essential member of any raid group.

While this build isn’t too different from the dungeon build, it definitely works better in a raid environment. Threat and range are less of an issue in a raid, so a shadow priest benefits from 5 points in Mental Agility in the discipline tree to help lower mana costs. You also won’t use Vampiric Embrace in a raid, as it typically does more harm than good for you. You’ll still have access to Inner Focus, which grants a mana-free Mind Blast with a great chance to crit.
Since the beginning of beta, we’ve seen a lot of bug reports around the Hunter class in particular, and we’ve been working diligently over the past weeks to shore up some of the issues that players have been reporting to us. We felt that it would be helpful to post an update on our progress as well as to clear up some confusion around issues that were reported that are behaving consistently with the Reference client and are not considered to be actual bugs.
Quest helper addons like Questie are a must have and will make your leveling experience much smoother. Over the years, Blizzard has reworked WoW's questing interface to make it more user friendly and to present more information. In Classic, that was not the case. Quests were not readily displayed on the map, enemies did not have text to indicate you should kill them for a quest you had, and items did not have the glowing lines or sparkles around them to let you know that you should interact with them for a quest.