Reddit mentions of IP Routing on Cisco IOS, IOS XE, and IOS XR: An Essential Guide to Understanding and Implementing IP Routing Protocols (Networking Technology)

i want to start with noting that what most people say below about this being a rather difficult track to find a "all in one" or even a "few in one" set of resources. I am working on my CCIE-SP so let me just go over a few things I am using that should help with your CCNP-SP.

• Routing-bits SP handbook - http://routing-bits.com/handbook-for-sp/
  
  
• INE ATC SP videos and workbooks - http://www.ine.com/self-paced/ccie-service-provider/bootcamps.htm (while the workbook may be overkill for the CCNP if you can get the videos on sale they would go a long way for you)
  
  
• This book - http://www.amazon.com/Routing-Cisco-IOS-Understanding-Implementing/dp/1587144239/ref=sr_1_1?ie=UTF8&qid=1422539055&sr=8-1&keywords=ios-xr+ios+xe
  
  
• Cisco VIRL - http://virl.cisco.com/ - this allows you to practice in an IOS/IOS-XE/IOS-XR environment for 150$.
  
  
• Fill in any gaps from either of the below reading lists - http://www.ine.com/resources/cciebooks.htm and https://learningnetwork.cisco.com/docs/DOC-10002 (many books on this list are absolute overkill but can be purchased used on amazon for cheap, like 2$ with 3.99$ shipping)

I'm nearly finished reading this book right now. The book goes into deep detail of the architecture of the IOS XR operating system. However, it does assume a base level of knowledge. For example, it very briefly covers configuring IGPs, but does not go very deep on that particular subject because the author assumes you already have that knowledge and experience (which it sounds like you do, so this book will probably be perfect for you).

What I have found by reading this book is that the syntax of IOS XR is generally not too different from classic IOS with regards to most generalized things. The biggest different with routing protocols is configuring based on address families, instead of just assuming IPv4 like classic IOS does.

There's another book (that I have not yet read) called IP Routing on Cisco IOS, IOS XE, and IOS-XR which I have heard is kind of like the updated replacement for Doyle's Routing TCP/IP.