We currently run all our Facebook posts through our Communication Director, who includes them in the general Seminary Facebook account. I feel like there are some trade-offs there, but I'm concerned that just the library (and the sub-set of the archives) wouldn't be big enough of a draw to get "liked" by as many of our current students, alumni, and friends. Does anyone else share an account with your larger institution? I'd be interested in tips for making that work effectively.

I like the "keep it short" advice, Lauren, and I'd add to it that you should always include a picture. Posts with pictures get considerably more comments and likes than posts without them.