Would any of the good people here know how to find an online copy of the Pentecostarion?

If you search Orthodox horologion there a website that gives you all the services with the peppers. Also the OCA website has the propers for major services but not the text of the service.

Thanks.

Check out the late great Archimandrite Ephrem (Lash)'s site: Anastasis. He'd translated the Triodion, Pentecostarion and much, much more. The translation is into accurate, literary, contemporary English!