Copra brought up the question at Blog Azeroth on What is a good guild?  The thing about this question is that every person will have a different type of guild that will fit them best.  So what then, determines what is the best guild for you?  How do you find your good guild?  Pixelated Executioner, Aggro Junkie, and Melted Faces all had some interesting thoughts on this topic.  The three main topics it boiled down to were the following:

1. Goals: PVE/PVP, hardcore/casual, dkp/loot council, progression, leveling.  These types of decisions are the foremost things when it comes to looking for a guild.
2. People: Whichever guild you're in, at the very minimum it should be a tolerable community.  It's best if you enjoy the guild community.  Doing a few instance/raid runs to get the feel of the community would be a good idea.  It's also nice if there is a friend in that particular guild.  Aggro Junkie mentions the guild culture, and Melted Faces talks about member treatment. 
3. Commitment: Your own performance and interaction with the guild.  Being able to pull your weight and being prepared with a good attitude is important. 

Rubymelon's #4: Time
This is all things that you should keep in mind when you're LF Good guild.  But there is one thing that I feel is the most important that is lacking from this list.  And this is time.  No matter how good the guild is, no matter how nice the people are, it just won't be the best guild for you if you have a time conflict.  Not only is it important to check what time the guild raids, but how frequently and on what days during the week.  Making sure that it doesn't overlap with classes or work, and making sure you won't be hungry because you have to raid during dinner time is very important.  Remember that while wow is a great game and a great community, it is only great if it meets your needs and time schedule.  I can tell you first hand that having raid as soon as you get home without time for dinner can be ok the first few times.  This also applies for when raid ends.  Are you going to get enough sleep before school or work Tomorrow?  Sleeping late from a new event such as Ulduar coming out is one thing, sleeping late everytime you raid is a different thing altogether.  But once this becomes fixed its the one way road to a messed up eating and sleeping schedule, bad health, and misery.  So here's the checklist:

• Does raid time overlap with my classes or work?
• Do I have time to get ready for raid?  (consumables, repairing, ect)
• Do I have time to eat and sleep?
• How frequently do I want to raid?  Am I going hardcore, or casual?
• Do I want to raid on the weekends?  Or have some off time to enjoy _____?

Once you have an idea for what type of guild is a good guild for you, here are some resources that will help you in making the next step:

• Elitest Jerks is the must go for the essentials you'll want to know about your class.
• World of Snarkcraft has some excellent guidelines for applying to guilds and todos and donots.
• Your Realm Forum is another spot to go when you're guild browsing.  Most if not all realm forums have a sticky post at the top with raid progressions, and different information representing that realm.  Sometimes guild websites are listed as well, so take the time to browse through their website and check the raiding times.  If it's not listed contact someone in that guild to find that out.  It's also a good idea to talk with some of their raiders to ask if the guild is consistant in keeping the scheduled raid times.  Don't forget not to pester raiders while they're in the middle of a raid!
  

While it may seem easier to sit in trade chat and spam LF good guild, people won't take you seriously, and there's little chance you may end up in a guild that fits your needs.  Not to mention that leaving a guild can end up being some sticky business, so it's best if you take the time to find a guild that fits.  What are some things you have observed or thought that are the elements of a good guild?  Is the guild bank an important element?  What about crafting, is that something that is important when you choose a guild?  What else?