B. Siciliano, O. Khatib, "Springer Handbook of Robotics", Springer Verlag
Roland Siegwart, Illah Reza Nourbakhsh and Davide Scaramuzza, "Introduction to Autonomous Mobile Robots", MIT Press.
S.K. Saha, "Introduction to Robotics", Tata McGraw-Hill Education
Richard M. Murray, Zexiang Li, Zexiang Li, S. Shankar Sastry, "A Mathematical Introduction to Robotic Manipulation", CRC Press
'Robotics' by University of Pennsylvania, GRASP Labs, www.edX.org
'Robotics' by Columbia University, www.edX.org
QUT Robot Academy
'Introduction to Robotics' by Dr. Oussama Khatib, Stanford University.
'Autonomous Mobile Robots', Autonomous Systems Lab, ETH Zurich, www.edX.org
'Underactuated Robotics', MIT, www.edX.org
'Robot Mechanics and Control', Seoul National University, www.edX.org
'Robotics Nanodegree' by Udacity
'Robotics' specialization by University of Pennsylvania, GRASP Labs, www.coursera.org
'Crash Course' - YouTube Channel. Courses on Computer Science, Statistics, Engineering, etc.
Khan Academy - Great for a fundamental understanding of topics in math and science
3Blue1brown YouTube Channel - A conceptual-visual explanation of difficult to grasp math topics
MIT OCW YouTube Channel - A collection of some interesting course lectures from MIT.
IEEE Spectrum - Some cool videos, DIY learning.
Note: All of the above content belong to their respective owners.