How to convert MTS/M2TS Video to iPod/iPhone etc.?

As Sony camera users, I’d like to share my experience on how to convert Sony MTS/M2TS videos into standard video formats and play them on a Computer, TV, or portable devices such as iPod, iPhone, Zune, PSP, as well as upload videos to share online.

Summary: This article consists of three chapters:

Chapter 1: Basic knowledge about MTS/M2TS

Chapter 2: Why convert MTS/M2TS to popular video formats?

Chapter 3: How to convert MTS/M2TS to popular video formats and upload to YouTube?