A good friend of mine wants to learn more about being transgender and the process of transitioning, more so the effects of T and what not.
What videos on youtube do you think would be the most beneficial to a cis-gender person wanting to learn more?

I'm a fan of SillyYetSuccint's channel on YouTube. It's a good start.

Just search the term "trans 101" or something similar on youtube, though you don't need a youtube vid to tell you the effects of T, they are readily available on many sites around the web.