My 1998 Mustang GT Won't Start!

Help needed please! My 1998 4.7L GT (22,000 miles) cranks but won't
start. This is a sudden occurrance. I drove the Mustang into the
garage, left town for a long trip, and returned to find a truly dead
battery. I replaced the battery with a new one from Ford. The engine
cranks and cranks but I don't get any ignition. I've gone through the
disarm sequence for the factory anti-theft, and done the same dance
with my aftermarket Clifford Avantguard III alarm. I've also checked
the fuel pump inertial reset switch but it seems fine. The fuel pump 20
amp fuse looks okay. How can I tell if the fuel pump or relay are
operating? Could my fuel filter be clogged? (Where is the fuel

For the life of me, I don't know what to do. I'm out of ideas and I
hate the thought of getting a tow to a dealer. I'll be vastly grateful
if anyone can guide me to a solution.

Many Thanks,