I have a question about FMLA. I Googled, but I'd like you to confirm that I understand correctly

Tim has to go in for surgery and he'll probably need me to stay home during his recovery. Is that covered under FMLA? When I looked it up, it said serious illness and I'm not sure if that would be covered.
I have no vacation time left and I don't trust my HR guy as far as I can throw him. I'd like to be able to walk into his office with as much understanding as possible.
If anyone else has ever used FMLA, your insight would be much appreciated.