Why pay when it's all free here?

for example you 

It's not as simple as that buddy.

Might I suggest this:

Learn the dos and dont's of reading, writing and recovering first.

From there, learn about ECU EEPROMs, (ECU Pairing, like IMMO off etc.). You won't learn how to do Immo Off etc, but you'll be clued up as to how different it is.

From there, it's onto mapping itself. More importantly how every ECU is different, and some revisions have different map styles or locations, etc etc etc.
Learn how to use tools like WinOLS with map files, but also how to make your own templates/DAMOS files etc by finding maps.

There's lots of information here and around various other websites/forums on many different types of ECUs. Have a look around and don't be afraid to ask. If you're ever unsure, don't just send it. You might screw up an ECU and that's no fun, despite it being part of the journey.

I agree. 99% of my understanding came from analyzing logs and comparing that with the maps and the FR. When you see the values line up 100% with exactly what you'd expect, you know you are on the right track.