If there was a list it would be ongoing lol.
You will need to buy feed, vet bills, dentist, farrier as a minimum really then there will be tack and bedding and stuff
The costs depends a lot of where you're gonna' have your horse, it's needs, how much food it's gonna eat and so on.
I would say the total cost every month would be between 250$ all the way up to 625$ depending on all the needs.
Otherwise, read here: http://www.horseandhound.co.uk/forums/showthread.php?452455-Costs-Of-Owning-A-Horse