Plus, some very easy to understand and follow books:
- from www.microchip.com, datasheets + application notes + sample codes, free MPLAB assembler/simulator.
- Books: Easy PIC'n, PIC'n and the Pace, PIC cookbook vol.1 and vol.2, A beginner guide to PIC, ... on this forum, try to search.
If you are familiar to AVR, so PIC is quite easy for you even with assembly.