Here’s a list of information I’ve stumbled across while trying to come up to speed on precision GPS.  I’ve made no attempt to make it a comprehensive list, just things I’ve found particularly interesting or useful.

I started my journey into the world of GPS by taking the Stanford online course and reading the Misra/Eng book used in the course.  I found both to be extremely informative and well done and would highly recommend both of them to anyone interested in the subject.

Recommended GPS books:

Global Positioning System:Signals, Measurements, and Performance (Misra/Eng):  

Recommended Online GPS Courses:

Stanford:  GPS: An Introduction to Satellite Navigation (Enge, van Diggelen)

RTKLIB info:

RTKLIB website
RTKLIB source code 2.4.3 beta (Github)
RTKLIB source code 2.4.2 stable (Github)
RTKLIB User Manual

My RTKLIB code and raw data:

My GitHub code repository
My RTKLIB executables
Raw GPS data sets

RTKLIB articles/papers/thesis:

Eval of Multi-GNSS RTK performance with u-blox NEO-M8N receivers (Takasu)
Low-costGPS/GLONASSPrecisePositioning Algorithm
(PhD Thesis: Carcanague)
Low-Cost, Single-Frequency GPS/GLONASS RTK for Road Users (Article: Carcanague)

Ublox GPS receiver info:

Neo-M8 Receiver Description
u-center Ublox eval software download
u-center Ublox eval software User Guide
Ublox GPS antenna app notes

GPS articles/papers/thesis:

The LAMBDA method for integer ambiguity estimation: implementation aspects
GLONASS ambiguity resolution

Demystifying GLONASS Inter-Frequency Carrier Phase Biases
A RAIM approach to GNSS outlier and cycle slip detection using L1 carrier phase time-differences

RTKLIB/GPS tutorials/blogs:

RTKLIB Guide for u-blox Neo-M8N (tutorial for real-time positioning)
Debian su hardware obsoleto 
Sub Centimeter GPS With RTKLIB
(short tutorial)
Michele’s GNSS blog