Simply, the best introductory book into electronics you can buy. Inexpensive, detailed, and easy-to read. Get it! Get it now, now, now!
Create your own Arduino-based designs, gain in-depth knowledge of the architecture of Arduino, and learn the user-friendly Arduino language all in the context of practical projects that you can build yourself at home.
Put your own ideas, diagrams, calculations & notes down in these 150 pages of engineering graph paper, with handy page marker, and STICKERS!
123 PIC Microcontroller Experiments for the Evil Genius is a excellent starting resource for anyone interested in the PIC Microcontroller.
Making PIC-based Laboratory Instruments and Controllers by Harprit Singh Sandhu is hands on tutorial and resource book that teaches you how to build your own interfaces.
Running motors with PIC microcontrollers is a hands on tutorial on running all sorts of small motors with PICBasic and PIC Microcontrollers.
Gordon McComb's Robot Builders Bonanza - 4th Ed. is considered by many to be the bible of hobby robotics.
123 Robotics Experiments for the Evil Genius by Myke Predko is a great starting point for anyone who is just interested in either electronics or robotics.
A quick, hands-on introduction to the popular open-source language.