Online Electronics Tutorials and Books
 General electronics theory
Electronics Club Great set of tutorials for beginners. You can find basics about electronics components, logic circuits, projects and so on...
All About Circuits Online version of the great free ebook by Tony R. Kuphaldt, highly recommended!
The Resistor Guide Online reference on all resistive elements, such as resistors, potentiometers, varistors, thermistors and more.
 Soldering and practical skills
 PCB layout and CAD
Dave's PCB layout tutorial
Quick-teck PCB design technical articlesSome interesting Engineering notes
Analog vs Digital Ground Interesting read on mixed signal pcb layout
Quick turn PCB prototype serviceA good PCB manuafacturing in fast delivery, high quality and low costs
Hitex insider guidesGuides for several ARM based MCUs