There is very limited on-street parking, however most of it in Nottingham is now on meters. Not sure of the area out towards Meadow Lane and Trent Bridge however, but when the council are in the process of attempting to tax people parking at work, it wouldn't surprise me if this is all on meters now.
There are a number of car parks in the centre and near the station which can be used, however will cost more than the park and ride. Buses from there are every 7 minutes now so is a regular, efficient service.
You're also right about the normal 'Footie' car parks that spring up on match day, Stanley, though for people heading into the centre for a drink before hand, I would go for the park and ride first.
More details on the Nottingham City Transport site: http://www.nctx.co.uk