http://www.bikepa.com/routes/index.htm - here are the PA routes
http://www.deldot.net/static/pubs_forms/manuals/maps/orderform.htm - here you can order the delaware bicycle maps that are extremely useful. (in my opinion) they're free and made of vinyl!
http://www.mybikesite.com/pennsylvania/ - not too good, but there's usually people on there looking for and selling fairly decent bikes
http://www.pahighways.com/OtherHwys/BicyclePA.html - i highly recommend this site, it contains detailed information on routes extending as far as west virginia and ohio.