One of the beauties about Greyhawk is that there is not a lot of detail in the setting, leaving it open for fleshing out by DMs and players. That said, there is a good deal of info on Pelor, if you know where to look. From the Ashes has a fairly detailed description of him, as does the 1e Gazetteer. Deities and Demigods (3e) as well as Legends and Lore (1e) also have detailed write-ups. Pelor's faith has a simple hierarchy. They are not so engrossed with rules and regulations to require a bureaucratic structure. Many shrines and temples to Pelor are composed of little more than faithful followers under the guidance of a patriarch (8th level or higher) and one or two acolytes. For the most part, priests live simple lives, hold services on Godsday and holidays, spend much of their time aiding the poor and wounded, and offer a variety of social services for their communities. High Priests of the church (9th level or higher) occasionally meet in a central location like the City of Greyhawk to discuss church doctrine and take care of church business, but the meetings are fairly informal and ruled by democratic consensus in most situations. Servants of Pelor are expected to defend their communities if attacked by evil forces, enemy nations, and especially the undead, hence many of them have been taught the use of at least rudimentary weapons, although their vows prevent them from using edged weapons. The primary object of a priest of Pelor in an adventuring party is to serve as a source of healing and a font of wisdom and spiritual guidance for the other members. Priests of Pelor are loathe to associate with anyone of evil alignment although they are equally tolerant of law and chaos, with a slight preference for law. Priests of Pelor pray for spells at dawn.