The best school secretaries make it look easy. You know the old saying about a duck bobbling along slowly on the water, while his feet are paddling madly underneath? That's a good school secretary! At least in this area, a lot is expected for a little (pay).
First and foremost, you MUST be professional, and extremely discreet. Secretaries know where all the skeletons are buried, and have to make sure they stay that way

. Seriously, though, you will have access to all sorts of data, student records, etc, and none of it can be shared without permission, even casually or to be "helpful".
Second, you MUST be a multitasker. You probably have huge long and short term projects on the computer due in the next days/weeks/months, and yet you will rarely get any amount of uninterrupted time in a row to work on them. In the same vein, you must be good at prioritizing, because every "fire" will think it needs to be put out first

. If you are lucky, you will get training when technology is updated/changes, if not, you will be expected to learn it on your own, around everything else that you already do.
Third, in a small school district you will tons of different hats (whether or not you have any training in them). You may be called on to do any other support staff work that there is a need for, you will probably run interference for the administration, you may well be the athletic department's "right hand man", etc, etc. This can be fun, and make work diverse, but don't forget those reports that need to be turned into the state by next week!
As a classroom aid, you have probably developed some very very close relationships with some (if not all) of your students, for good or bad. Although you will "know" all of the students as a secretary, you will not have time to chat and make friends with them the way you did in the classroom. There just isn't time!
I've known school secretaries who are absolutely worth their weight in solid gold, even at today's prices

. Unfortunately, with the added pressures, higher expectations, and lower pay that we are seeing today, we're also seeing more turnover than what we have in the past. If you are in a good school district, that values it's secretaries, and you think it would be a good change of pace, go for it!
Terri