Getting to the ground
Unusually for a new ground, Rotherham's is closer to the town centre and station than the one it replaced. It's only a 10 minute walk from the station, and the same or less from any pub you're liable to end up in. If you're driving down then there's no parking at the ground. There are number of pay & display car parks around the town centre. If you get down reasonably early you'll be able to park for nowt in the streets near the old ground.
I haven't come across any reports of pubs to avoid, although you should probably use discretion if you try any pub not mentioned below. It seems that the Bridge Inn, very close to the station, is definitely worth a try. It welcomes away fans, has a decent selection of cask ales, and is reasonably cheap. Two other recommended pubs are the Cutlers Arms and New York Tavern (no less than12 hand pumps), which are both on Westgate. However, they both don't open until 12. I can personally vouch for the latter of the two being a cracking little pub. There are naturally a couple of Wetherspoons outlets. The Rhinoceros is the closer of the two to the station. A better bet is the Blue Coat as it's a bit further from the station and therefore probably quieter, plus it's a bit more upmarket.
Official site (including away fans' section)