I was reading about employee orientation (I work in marketing, so this kind of stuff is part of my day) and it occurred to me that this would probably be a great way to conduct recruit "orientation" in guilds (because I am a nerd…) so here it is, with adjustments for WoW :D

The 10 Commandments of Onboarding
Rules to live – and work – by for a divine onboarding experience.

Thou shalt not bear false witness against thy recruit. Few things are more disappointing than the realization that the guild you thought you were joining is sorely different than what you were led to believe. As a recruiter, misrepresenting your guild's progress or the recruit's new role (recruiting a tank and making them raid as DPS etc) destroys trust in you immediately, after which no amount of orientation efforts can undo the initial damage.
Thou shalt have a written plan of recruit objectives and responsibilities. Make sure you direct the new recruit to a place detailing guild rules, raiding times, loot rules and any other objectives. This is usually found on a forum, so ensure the recruit has registered and can access the forum immediately upon joining, and direct them to the information (not just "go to forum plx"). If this information is spread among different forum posts, collect the links in one Recruit SOS post. This helps diminish any confusion for new recruits and instead opens up the floor to discuss concerns or ideas.
Thou shalt give thy recruit thy undivided attention. Letting trial periods drag on, being slow to respond to questions/whispers or not giving clear assignments to new recruits sends the message, "I'm just not that into you" and kills morale. Take time to acknowledge the new recruit (a simple "hello" when they log on is a big step for little effort), prepare a checklist of subjects to review with your new recruit (spec/gem concerns if any, primary raiding role etc) and set aside the appropriate amount of time to do it. This doesn't have to take long, and gives new recruits the message that they are important to the guild.
Thou shalt have relevant paperwork ready. Make sure you give the recruit information about where to get information (see Recruitment SOS post idea above), what communication means your guild uses and how you schedule raids on day one. This way, you don't have to waste time dealing with it later, and your recruit can start getting required add-ons, set up Vent and sign up for raids immediately.
Thou shalt introduce thy recruit to thy guildies. If your guild does not discuss applications publicly, introduce the recruit and their spec/role when they join. Encourage class/role leaders to discuss ways in which their roles interact with that of the new recruit, and how they might expect to work together in the future. (This is also a good time to introduce the recruit to their class leader as an immediate resource for any questions and key information about guild structure and goals.)
Thou shall set up thy recruit's raiding position. The first raid with a new guild is very stressful to a new employee. Before a recruit's first raid, make sure they understand rules about the guild bank, attendance time, class/role specific chat channels and raid ettiquette. Make sure class leaders are informed of the spec of the new recruit so that they can assign them a role that suits them and make sure the recruit knows who to talk to if they have any questions.
Thou shalt schedule one-on-one time to ensure you connect regularly with the new recruit. If you can't do this on a weekly or bi-weekly basis for the first month or so, ensure that someone is checking up on them and how they feel in their new guild.
Thou shalt create a balance. The first raid is always tough. If the recruit is attending an encounter for the first time as well, make sure that they don't get too overwhelmed – try bringing a new recruit to encounters that are safely on farm for their first time, so that they can focus on learning how to work with the team in a relatively safe environment.
Thou shalt clarify the guild culture. Again, to avoid future confusion (or embarrassment), provide the recruit with guild information, policies – including loot rules and late policies – and privileges. A tip about guild chat humor and any unacceptable behavior should be addressed.
Thou shalt think beyond the first few days. After the trial period, request formal feedback on the new recruit's performance from his or her class/role leader, and be sure to solicit feedback from the recruit as well. Take this opportunity to address any issues of concern as well as note any accomplishments so that all parties are confident that the new recruit is poised for success in his or her role.

This may seem like an awful lot of work, but is really as simple as collecting the basic information your guild runs by in one place and making sure that a new recruit can access it, introducing them to their "team-mates" and checking up on them a couple of times. These measures, however, can make a new recruit adjust to and contribute to your guild much faster, and saves officers a lot of time during the raids when questions would arise.