The simplest way is to go to www.pavotes.com. You can register there or download a paper form to mail in or take to the Lehigh County Voter Registration Office at 17 S 7th St, Allentown, PA, 18101. Questions, call them at (610) 782-3194.
For your convenience, here are the paper forms to use.
If you will be 18 on November 6th, you can register NOW. You must register one month before the election, but my advice is register as early as you can. You will receive a voter card in about two weeks via snail mail, but you’ll want to double check your registration here, in case of a snafu.
If it’s your first time voting at a new polling place, take your photo I.D. Otherwise, you don’t need it. I always take mine anyway, along with my voter registration card, JUST IN CASE. You just never know!
Note that if you are a currently incarcerated felon, you may not vote, but if you are a felon on parole, incarcerated for a demeanor infraction, or awaiting trial, YOU ARE ELIGIBLE TO VOTE.