I will open with this. Ask your admin for their input and follow any district guidelines in place. Whether you like the guidelines or not. That is always the smart thing to do. My admin said OK and since the district doesn't have any real prohibitions in place I went for it. I will be sad if I have to ever delete it because of policy changes. But I will. Begrudgingly. And then start the discussion as to why the policy should be changed BACK.
Also ... I don't post any pics with kids in them unless I've digitally stamped out their faces (in Picmonkey with a smiley face or emoticon ... the blurred out faces some bloggers do sort of creeps me out). Check out my page (look at the tabs underneath my blog header) on simple photo editing if you don't know how to do that.
Now ... a major distinction that may need clarification. A Fan Page is NOT the same thing as a regular FB account. It's not reciprocal like when you "friend" someone. A Fan Page allows an entity (a school library, or school, or website, or business, or church group, or WHATEVER) to share information with people in an arena where many are already spending time. Kind of like "go to their hangouts and they will come." If nothing else set up a Fan Page to post a status when you update something on the school webpage. People may not remember to GO to the school webpage (not everyone knows how to use RSS feeds!) so if you post on FB (where they already are) with the link to the new page content? They'll remember to go check it out!
You could choose either organization, institution, or community, I think. Haven't ever seen any hard or fast guidelines and the case could be made for all three. Since you can't really see the link know that it's here. And here Techipedia does a VERY nice how-to. Nicer than this one. This is more a "why" and plea to not freak out over the idea.
People who "like" your fan page do NOT see your personal information and (depending on their privacy settings on their personal pages) you can't see theirs. It's not like the friends that show up in YOUR newsfeed. You won't see all of the posts by people who've liked the page in your newsfeed. The Fan Page posts WILL show up in THEIR newsfeeds. There are different permissions you can secure to keep other people from making random wall posts on the fan page.
Now. Just tonight example. A friend commented on a post I made as our Fan Page. And one of HER friends liked a comment I made in response. She could see it because our mutual friend had commented on the Fan Page post. Now, if I've got this right that's in our FRIEND's settings and you can't do a whole lot about that (see this status update Snopes article). If it ever became a problem then you would be able to block someone who had liked your page.
I'm actually not sure myself about that "Default visibility of posts by others ...." Will have to research that one. And ... in the interests of full disclosure ... I actually had it so that everyone could post to our timeline and add photos and videos. Decided to change that tonight even though it hasn't been a problem in the ... six months? Maybe seven we've had ours. Not like people felt a great need to post things on our Fan Page wall. They just commented on posts. ;]
I don't have a huge percentage of parents or staff who participate yet but the ones who do? Appreciate when I share something for either group (and I do post new books, literacy ideas, book trailers, activities we're doing in the library for both staff and parents). I haven't worked all that hard to advertise it so far. Got a banner last spring from Vistaprint with a QR code for our page on it. Then packed it away for the summer and now can't remember where I packed it. #oops