I have a tenant that I have repeatedly tried to work with over the course of his lease regarding paying the rent. It has gotten to the point where I can no longer deal with his inability to pay.

Including late fees, he is currently $1,985 behind on rent. That's $625/month (@ 3 months) plus a couple late fees. He does make "infrequent" payments that are never enough to cover the current month's rent and late fees.

During my last conversation with him, I told him - "Last chance, pay $500 every other week for the remainder of lease or your out". His chance to pay is coming due by the end of this week and I would like to be prepared in the event he misses payment.

My questions are these:
1) How many days notice am I required to give for a "pay rent or quit" notice in PA? I believe it's three or five, but can't locate the info.
2) Once served with this notice, and the days have elapsed, then do I file eviction papers at the courthouse?
3) Am I missing any important steps?

By allowing him to make "infrequent" payments you may well have voided the actual lease, since you were allowing payments out of the written lease. If the other party takes proof of this to court. ( most likely he won't)

You have to have proof that he was given the notice. ( sorry I did not find PA, but here they get a 20 day notice)
If you go down to the court where you file for eviction proceedings, often they have a printed form showing you requirements, or they may tell you.

Once you file for eviction at the court house, they will serve him with papers for a court hearing, you have to go to the hearing and present your case.

Then they will issue an eviction notice.

It's 10 days in PA (except for Mobile Home Parks).

See (a) and (b) here:
http://members.aol.com/StatutesPA/68PA250.501.html

To see the PA Landlord and Tenant contents, start here:
http://members.aol.com/StatutesPA/68.Cp.8.html