Good Mentors will be friends, companions, a place to go to for advise, sage or otherwise. Many mentees move on to become guildmates, though some do not. A good Mentor/Mentee relationship usually becomes lifelong (or at least stay-in-egypt-long).
There is the standard "brick and board", or island mentoring. This is a valuable service to Egypt, as if a new immigrant doesn't make it off of the island they have a zero chance to become a good citizen. This is a task that everyone in Egypt can and should do from time to time. An immigration guide is availabe
Also we have a list of common questions asked by new players.
At this point if all goes well you'll have someone who is at least interested in what we are about. What I do now is instruct the new citizen to visit all of the local Universities in order to get caught up on skills, and sign up for each of the initiations. It is a good idea to help them get mineralogy also, either by loaning them the iron and copper, or by teaching it (as it's one of the few school skills that can be taught). Also might want to mention about the fact that this is the legacy of Naeem Akil, maybe use this time to tell his story if you know it.
At this point you yourself might be wanting to leave for RL obligations (if not you will sometime), and as such a Mentoring Guilds is a good thing to be affiliated with. If you yourself are not involved with one, I'd suggest that you get ahold of one, or start one yourself (keeping in mind for it to be effective you will want experienced mentors online for most of the times mentees might be). Also making sure that the citizen has the web locations written down: wiki.atitd.net, and atitd.net. It also is a good idea to go over the commands. All this can be done while the Citizen is doing their University run. It is a good time to emphasize that much here is not in a "this is your path" kind of way. Yes there are tests, and as a society we must complete them, but there is nothing saying an individual needs to do them. Either at all, or in any order. The goal of this game, as in any other is to have FUN. For examples of things people have accomplished that were not test related see here. Remember as a mentor you are the person's link to the community. You might want to introduce them to local guilds. Get them into large chat channels. Teach them and be their friend and this will be extremely rewarding for both you and them.
Also . . . some Mentees don't decide to play. This is normal and means nothing when it comes to your mentoring skills. Some decide to play, some don't. Just keep hanging in there and you will be a mentor that people talk about and come to for advice.