Officers need jobs.
Too often officers are just the mates of the dude who happened to start the charter for the guild, or the original people who signed it for no really good reason. This is so BAD it is ridiculous. If you are serious about a guild, dont pick your mates to run it with.
There are some pretty obvious admin jobs that need doing in a successful guild, here are a few of them:
Raid leaders - these are the people (usually 2) who run the raids. They organise the strat, explain it to your nub raiders then cry as they watch their beautifully planned strat butchered by people who stand in fires. You need these people to have the power to dump people from raids, and from the guild if need be. They need power with responsibility, and they need a support network.
Raid Assists - these guys are your section leaders (what used to be called Class Leaders back in 40man days). there are 3-4 sections; Tanks/melee, healers, ranged. Each section needs at least 2 leaders. One to whip them into shape and get them organised and actually IN the raid (who is available, do we need to recruit, do invites on the night to the raid, set up any mads that need setting etc) and one for technical questions about class mechanics. The latter should be a complete nerd theorycrafter who lives in EJ.
Loot Masters - these guys have the unenviable job of distributing loot with whatever system you chose (post on that later). Often they are in charge of making the guild bank money as well.
Guild leaders - this is you and perhaps a couple of the above people as well. You guys make decisions about the ultimate goals of the guild, keep your reputation in check, and generally make sure you have a happy guild. This is a thankless job. Keep this group to 2 or 3 people. Too many cooks spoils the guild.
Webmaster - you need one of these. A good guild is an organised guild and a webpage is essential. Use a premade one or if you have someone that can run a custom one, make sure they are included in officers. Often people will wonder why they are there, but they have full website access, they know everything that is going on. Make them an officer and they will be much more inclined to be awesome as you are showing respect.