Brian's PIC Page
Microchip has a very nice web site. They offer the extensive line of PIC microcontrollers as well as serial EEPROM and some other neat products.
A new player offering a very fast PIC compatable controller is Scenix. They have several application notes that allow you to create peripheral functions such as serial UARTs, A/D Converters, using software.
Peter Anderson has a nice PIC page.
Here is a PIC programmer that I plan on building.
Wirz Electronics has low cost tools and information on PIC and AVR controllers.
Don McKenzie runs Dontronics. His page is full of PIC and AVR tools and information. His single board computers based on the PIC and AVR chips are a great low cost way to get started with microcontrollers. The boards are very small and could be integrated into a variety of applications.
A nice page that I just found has good stuff to get started with the PIC is by Myke Predko. He has a book that looks interesting as well as links to more PIC information.
The GNUPIC Project has lots of tools and source code for free.