You could include poems or short stories wrriten by kids of employees, new ventures of the company, achievements of the month. You could also add puzzles,quiz,one write up from senior manager (you could keep it on rotational basis) recent ocassions in the company and not to forget general articles which would convey some message to all ( it could be a social message too!)
And if you wish to keep it only H.R related magazine then articles on team,leadership could be taken into account.
That's all from my side. Hope it does prove to be of some help to you.