What is it that you want to do on social? Just post page posts to Facebook (for example) or do you want to create, optimise, promote and measure social campaigns? Or do both! I think this is pretty important for you to define first and then you’ll be able to make some judgements on resource.
In my school, I manage all socials – that includes the day to day posts across 4 platforms and also our paid social campaigns. They are not sit and forget and I invest a lot of my time into creating the content and then ensuring they are optimised throughout the campaign. I also need to create campaigns that hit each audience depending on where they are in the funnel — then there’s the re-targetng campaigns from Facebook pixels etc. I don’t think social can be regarded as simply posting posts to Facebook anymore, so personally I do feel it’s a full-time resource and a mixture of content creator and digital marketing savvyness.
Having said that, I don’t work full-time on social (perfect world). I’m the Marketing Manager at our school so my time has to be divided across many varied and wonderful things. Ideally, I’d love more resource in this space. We have 1,100 kids at our school, and I would say we are mid-tier fee.
As far as how active – trial and error will see what works best for your school. For us, we post to FB about 3 times a week. Anymore than that and we find that FB does not show our content to our audience as the algorithm prefers friends and family posts over business pages. Instagram, we might post once or twice a day – sometimes more sometimes less.
Feel free to contact me if you want to chat.