Need train details from Philadelphia to Wakefield
check www.mbta.com for commuter rail schedules and fares
Oops! Should mention that coming into Boston from Philly, you will arrive at SOUTH station... the commuter trains to Wakefield depart NORTH Station. The website will also give you information about subway connections between the 2 station. Unfortunately, there is no DIRECT link between the two... if you have luggage, the easiest option is take a cab from South Station to North Station. Boston is a small town, and it's a relatively short distance.
You can get off the train at Back Bay Station instead of South Station; the fare is the same and all trains make both stops. At Back Bay, transfer to the MBTA Orange Line ($1.25 fare.) Catch a train bound for Oak Grove and ride to North Station, the sixth stop.
At North Station, when you've passed through the turnstiles walk into the passageway under Causeway St and go to the building just ahead at the top of the stairs. That's the commuter rail station (as well as what's now being called the TD BankNorth Garden, our sports/concert arena.) You can buy your ticket to Wakefield at a window there; the train bound for Haverhill is the one you'll catch. The timetables are posted on the MBTA Website mentioned already.