I think these videos will help you

1- https://www.youtube.com/watch?v=c5SsN5RzAPE

2- https://www.youtube.com/watch?v=yjv0FDbwU5Y

3-https://www.youtube.com/watch?v=HBkbDJGybzk

4-https://www.youtube.com/watch?v=qIWYvThmYXA

You can check out these books: PIC Microcontroller Project Book by J. Iovine, Advanced PIC microcontroller projects in C: from USB to RTOS with the PIC 18F series by D. Ibrahim, and PIC microcontroller: an introduction to software and hardware interfacing by HW Huang. I've attached the links to these books. Good luck!

http://doi.contentdirections.com/mr/mgh.jsp?doi=10.1036/0071437045

https://www.google.com/books?hl=com&lr=&id=NPSQShtCQaUC&oi=fnd&pg=PP2&dq=PIC+Microcontroller&ots=DB7fZU_TRA&sig=6yO-R-fhbijcI-3uaRCBnIp3QmU&redir_esc=y#v=onepage&q=PIC%20Microcontroller&f=false

https://www.google.com/books?hl=com&lr=&id=CB9GaAU1dwsC&oi=fnd&pg=PR21&dq=PIC+Microcontroller&ots=HhccE6ry3h&sig=b253L1UWoiul1yE5m9HAHfs6u_4&redir_esc=y#v=onepage&q=PIC%20Microcontroller&f=false

• I think you can download some example code in the Internet and buy a Board to demo it. You will understand more. 
• I have some website .. I hope it will helpfull with you.
• http://embedded-lab.com/blog/?page_id=26
• http://en.wikibooks.org/wiki/Embedded_Systems/PIC_Microcontroller

Reading book and paper is waste of time. Just by hardware and get started. I am saying from my experiance

I think :

first you must  have a good knowledge of C and computer Architecture,

second start reading the book "Advanced PIC Microcontroller Projects in C" with applying projects based on PIC

its good to have a development board like easyPIC which give you a short way to learn by embedded example.

http://www.mikroe.com/easypic/