So i spend most of my time looking around at computer components on sparfun and taydaelectronics and such although I find that I don't understand alot.
Especially on Instructables.

Are there any basic guides and tutorials and such that would go through the basics of a circuit (resistance, capacitation, power, etc.) and also the basics of communication between microcontrollers and recieving data and such?

The project of the single flashing led, in the tutorial you said, they have a 150 ohm resistor with the LED.
I've done the same project on the arduino using the integrated resistor with pin 13.
I'm wondering why 150 ohm? Why not 490 ohm, or something else? Wheres the math?

EDIT: Nvm i found the math. WOW this tutorial is great!! especially with explaining the 74HC595 Shift Registar