First I want to welcome you, to the teaching profession!! My wife, and myself are both long time teachers 28 years each.
Like many before have said, the S/D Resorts are the only places on Disney property that have a teacher discount. We stayed at the Swan several years back, and found it comfortable. The rooms sizes are average, DBL beds. They are close to both Epcot and Disney Studios by boat. That's a great advantage for us, since we love Epcot and the Studios. One thing though, neither is "Disney themed", if thats important to you.
The teacher resource center at Epcot is long gone. I used it in 86' and found it to be very useful, and full of great resources for all grade levels. I'm sorry to have seen it go.