I can suggest "Human Resource Management" by Gary Dessler, "The HR Scorecard" by Brian Becker, Mark Huselid and Dave Ulrich, and finally "Predictive HR Analytics: Mastering the HR Metric" by Kirsten & Martin Edwards. I think these are the only books you will need for your questions. We have organized a couple of similar charity organizations some years ago with the support of some book houses in Greece and these are the books that helped me in my studies.

Welcome to the community Constances.

When this happened to me, I arranged a meeting or two with my boss - the CEO and asked him what and why I was employed. You may get told as I did, that they need a HR department, so I then asked them what they wanted me to actually do - and that got answer like, reduce / advice and get down the sickness levels, tell us how to get rid of the shirkers, the idle, those on overtime fiddles and the useless employees. (We'd taken over 25 local authority care homes)

Over the next month I tried to meet individual managers to find out what they were struggling with and then work started to come in from managers; "What do I do about XX whose refusing to carry out some of his duties?, and so on.

So ask your line manager or boss and ask the managers who work in the charity what they want you to do or need.

The more you ask questions the more information you'll get back about their HR needs and wants and things they were'nt even doing!