(All prices are as at 2016)
Getting to the ground
The ground is a good 30-35 minute walk from the station. An alternative to walking it is to catch the 19 bus from the bus station. It runs every 8 minutes, and the fare is £1.60 each way.
If you're driving, one recommendation for avoiding the worst of the traffic is to leave the M6 at junction 31a. There's effectively no parking at the ground. There is though street parking not far away, in the area around Victoria Road for example. Alternatively you can then park at Sumners (£3, but you get this back when you spend in the pub) or at St Gregory's Social Club (also 3 quid).
The aforementioned Sumners is one of the closest the ground, and fortunately it welcomes away fans. It's struggling to survive mind and gets pretty poor reviews, and the only food they do on match days is a carvery. Another option is St Gregory's Social Club. They charge a quid admission, but once inside the beer and food are cheap. There are loads of pubs in the city centre, particularly along Friargate. However, it sounds like many of them won't serve away fans, and even if they will the police are liable to move you on. I'm sure there must be some places that are ok though. There are a couple of Wetherspoons outlets. The nearest to the station is the Grey Friar. It could be worth giving it a try because even if you can't get in you can always head to the nearby Blue Bell, which you can be pretty sure will be sound. The Blue Bell is Sam Smiths, and therefore dirt cheap, and it gets excellent reviews. Plus it's only a 3 minute walk to the bus station if you want to jump on a bus to the ground. My personal recommendation though is the Moorbrook. It gets fantastic reviews (even scoring an unheard of 9 out of 10 on www.beerintheevening.com), and it's far enough from both the ground and city centre that it hopefully shouldn't get too busy. It doesn't open until 12 normally, but it's likely to open at 11 on a match day.
National Football Museum