http://www.robotplatform.com Comprehensive robot building guide and Electronics reference site http://www.robotplatform.com/knowledge/servo/servo_tutorial.html Servo Motor is a device which uses error-sensing feedback signals to determine and control the position of a motor shaft. The term "servomechanism" closely relates to servo motors.. http://www.robotplatform.com/howto/L293/motor_driver_1.html For robots to do work, you need to know how to control a motor. L293D is a cleverly packed IC which can control two DC motors in both directions: forwards and reverse. Here is a detailed explanation of building a board based on L293D IC http://www.robotplatform.com/howto/dev_board/atmega8_dev_board_1.html A great step-by-step tutorial on building your own Atmel AVR based Atmega8 development board. The board is ideal for beginners with detailed explanation and pictures.. http://www.robotplatform.com/howto/pcb%20etching/pcb_etching_1.html If you are seriously into electronics and robotics, then there is always a feel to ditch soldering and get your own professionally designed circuit board. Etching is a technique used to quickly make professional looking PCB's with limited resources http://www.robotplatform.com/knowledge/ADC/adc_tutorial.html Analog to Digital converter is an electronic device which converts analog signal from our real world into a machine readable or binary or digital format. For this all you need is a component which can convert physical real world analog signals into voltage signals.. http://www.robotplatform.com/electronics/photoresistor/photoresistor.html Photoresistors, also known as Light Dependent Resistor (LDR), Cadmium Sulfide cells (CDS cells), Photoconductor and sometimes simply Photocells are a type of transducer which converts energy from one form to another where one of the known forms is electrical energy.. http://www.robotplatform.com/knowledge/Atomic%20Theory/atomic_theory.html Atomic theory is the back bone for electronics. Here is a nice explaination on how electrons work within an atom. It also tells you different types of shells, energy levels... http://www.robotplatform.com/electronics/electricity/electricity.html How electricity works, and how is it generated from an atom. What are protons, electrons and neutrons. Read further to know how current flows .. http://www.robotplatform.com/howto/blinker/blinker_1.html Ever wondered how to program a microcontroller? This step by step guide helps you in microcontroller programming; http://www.robotplatform.com/howto/serial%20programmer/AVR_S_Programmer.html There are different types of microcontroller programmers available in the market. But what if you need to build one? Follow this article to build your own serial programmer. Not the best, but serves your programming purpose http://www.robotplatform.com/knowledge/AVR%20Basics/avr_basics.html Microcontroller can be termed as a mini computer with all peripherals on the chip. AVR is one such microcontroller of choice in hobbyist community. Learn more about AVR... http://www.robotplatform.com/electronics/capacitor/capacitor.html Capacitor is one of those fascinating devices which are horrible when they go wrong and absolute brilliance when they do their work. Here is a detailed explaination of capacitors and their applications..