Its very expensive to attend a game and there are good and bad seats in Fenway. Best seats for a family are in the Alcohol free section, grandstand 32 and 33. The seats face home plate and you have a great view of Wall and no drunks teaching your kids new bad words.
The worst seats are any seat in sections 5 through 10, where you must crank your neck to the left to see homeplate (the seats actually face the outfield, great for concerts and football, not so great for baseball.