Best turtorial/website for learning how to program switching microcontrollers?

[Nocaster Cat]

I want to delve into learning how to program microcontrollers for relay based true bypass switching. I know absolutely nothing about the process so the more in depth the tutorial, the better. Thanks in advance!

[samhay]

What type of microcontroller?

http://www.diystompboxes.com/smfforum/index.php?topic=42476.0

[Transmogrifox]

Pick a chip.  You won't go wrong with any platform for what you intend to do.  For example, I like TI's msp430's:
http://43oh.com/2010/08/10-beginner-msp430-tutorials-and-counting/

Order a demo board from AVR, PIC, TI, or ... well, I would recommend one of those 3. 
I really like this one:
https://store.ti.com/EZ430-F2013-MSP430-USB-Stick-Development-Tool-P800.aspx
It has a little stamp with through holes.  You can take it off the end of the USB stick and solder it right into one of your projects.  Really simple just to get started learning.

Then start with the most basic program:
blink an LED.
Change timing on LED blinking
Read an input pin and stop/start LED blink....
Then you're pretty much ready to start doing more interesting things.

Also some time ago I posted code for the MSP430 to do drive latching (or nonlatching alike) relays.  Here is the thread.  Could be useful if you end up settling on MSP430 series:
http://www.diystompboxes.com/smfforum/index.php?topic=109159.msg997329#msg997329

Even if you don't choose MSP430, you may find the basic concept useful -- it would be portable to any platform as long as you modify the initialization stuff to match the specific platform and clock frequency.