Im an officer on the Hellscream EU server, in one of the larger guilds, probably in the top 20-30 progression wise on our server, although thats not necessarily our main goal, so not actually important to us, as we're actually a casual, community raid guild, rather than a hardcore raid guild, but its nice to make some progress
First and foremost a tip for me would be, elect some good officers - experience is good, but not the most important. THE most important thing about officers is making sure they're mature, have a sense of patience, and get on with one another, or Officer chat will become very quickly quite an unpleasant place, when in actuality it should be fun, and also useful for talking to the others to plan/destress over people who've annoyed you etc - a sanctuary. In line with this comment, dont take all the responsibility for yourself, if you get a decent group of like-minded people to help you run the guild, let them help you run the guild! Sharing responsibility, rather than letting everything come down to you/guildmaster is a sure fire way of helping you keep the guild going rather than burning out, it also means when important decisions have to be made, you can do votes etc, rather than struggling to make a big decision by yourself.
Also, try to look ahead when inviting people, you dont have to be TOO stringent, but set a goal for your guild, and make this relevant when deciding whether to recruit people - for example, if you have a casual raid guild, yet a lot of hardcore desiring players etc, you're bound to hit a rock somewhere.
Aside from that, a site can help too, we used to use an invisionfree board for almost 2 years, but have just recently moved over to Guild Portal ourselves due to the extra features. It doesnt have everything I'd like, and has some bugs, but its generally very good, and doesnt cost much to get a referal on your url ie mastersoflight.guildportal.com
Bankwise, as said above, if you dont know if you need one, dont do one. They can be a lot of hassle to bother with, and unless the entire guild decides to use them, its virtually pointless, as you'll have a very limited number actually bother to use it.
If you decide to actually do some raiding when a lot more hit 70, I'd really recommend you make sure you get people to collect good gear, and perhaps heroic gear before starting, or the shock and frustration will be immense, the level 70 raids are a lot higher scaled than the start of the old level 60 raids (and dont really break you in in the same way- they get pretty hard pretty quick), and going in knowing its going to be damned tough, and with good gear, will help somewhat. Going into Kara with most greens wont cut it; people will really want to collect decent higher level blues for thier relevant job. Also, it'll help immensely if you make certain mods compulsory for them, as they'll help the raid do thier job better.
Ones I'd recommend for raiders would be CTRA/Equivalent raid monitoring addon, KLH Threatmeter (can be misleading, but can also be raid wipe saving), and perhaps Ventrilo or Teamspeak, as in the middle of combat, instructions are VERY hard to type properly.
On top of this, if you can get EVERYONE raiding to read up and become familiar on boss tactics, it'll be a lot easier for you, the raiding bosses tend to be a LOT more complicated and demanding than your average 5 man ones.
Boostwise, I cant discourage it enough, UNLESS someone high level offers occasionally; as you've already discovered, people tend to become lazy, and assume someone should always boost them, when in fact, at lower levels, you REALLY need the experience those dungeons give, both point, and play skill wise.
