Olbaid - you don't say what package style of ENC28J60 you have bought (or perhaps you bought the PicTail daughter board). I would suggest that you look at the ENC28J60 data sheet on the Microchip site as it contains all of the chip pin descriptions, or the PicTail data sheet.
For a library, have you looked at the link in response #7 (two above your post)?
Susan