Theres a car park at the ground (Cherry Street side) but will cost you £3. Theres street parking around but watch out for permit schemes knocking about. Towards the city centre there are variouas car parks within walking distance, that might be your best option.
I parked in a street vs Featherstone (Sunday) BUT there were notices all over stating that it was permit (residents only) Monday to Saturday 08:00 - 18:00