Pitfalls I would watch out for:
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Don't make the PC's found their own covenant from scratch. Playing a Spring covenant can be fun but it is simply too much work for an all-newbie troupe, IMO.
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On the other hand, do not have too many NPC magi present at the covenant. The more NPC's, the less important the PC's feel, and the more work the storyguide has to design and portray the NPC magi. Also, once the saga gets going, it becomes hard to justify why the NPC's don't get involved in all these important stories that are going on. I would recommend you have one kindly old NPC wizard and leave it at that; see also the "Superiors" hook in the Covenants chapter.
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Don't design the covenant with too many vis sources right off the bat. It is a lot easier to add more vis later than to take away sources if you've started with too much. Also, it is better to give out one-time finds of vis (through stories) than to be too generous with permanent sources. Getting the vis supply right is quite difficult IMO and I recommend starting with a miserly supply and gradually increasing it (over several game years).
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Pay attention to saga pacing. Magi advance more between stories than because of them, but with companions and grogs the opposite is usually true (unless your companions are bookworms).
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Don't overlook the fun to be had with grogs. Playing an all-grog session (perhaps the grogs go on a mission for that NPC magus) can be a good way to start. See also my "Grogs 101" thread.