I drank in The Peacock last season. It's right on the junction of London Road / Fletton Avenue / Glebe Road. From memory it had a good selection of lager and real ales. Plenty of street parking on the residential roads off Fletton Avenue too.
I think you will find that most of these roads are for residents' car parking only. The Posh fans tend to park further up London Road,past the Peacock going away from the stadium.