I was just on the tokyo metro (subway) last week, and noticed that the signs are starting to be english friendly. I've been going to downtown(Tokyo) for yrs. on my layovers in narita, and it's definitely getting easier for english speaking round eyes to navigate the subways nowadays.

I'll second what Huck said on going to KIX, but for anyone that just wants to go to downtown on a NRT layover, the Keisei Skyliner is much cheaper than the JR Narita express. Good luck
Z