Adding officers to your guild can help ease burdens on the Guild Master, and up efficiency within the guild. But poorly chosen or corrupt officers can do more harm than good within. Even before you select a cadre of officers, you should have an idea of what you'd like them to do for you. Let's take a look at the different types of officers you should consider having in your guild, and how they all interact with each other and your fellow guildies.
Class leaders are the first to come to mind. This type of authority should have a keen knowledge of the common specs and rotations for their class. They should be familiar with itemization for their charges and advocate for them in loot decisions.
Raid leaders are an absolute blessing for dungeon-crawling guilds. He or she can either be in charge of raiding as a whole or just fill in for the GM as needed. It is very helpful to assign an assistant Raid Leader to the Loot Master position so that the raid can continue with trash pulls as loot is distributed. Raid Leaders should be intimately familiar with the fights, and have enough patience to be able to explain them.