Android

First of all, here is a great resource for Android Noobs:

http://www.androidcentral.com/tips

There's tons of stuff on android there.  

Rooting:

Here's the Android Central post about rooting.  (http://www.androidcentral.com/what-rooting ) Essentially, rooting gives you access to systems files and features that are typically locked by the manufacturer and/or carrier.  For example, on some phones, rooting would give you the capability to overclock your processor from the factory set 1Ghz to something higher.  Often phones hardware is much better than the software that is installed from the factory.  The software often waters down the capabilities of the phone often to yield better battery life or a more stable user experience.  Rooting really isn't for the faint at heart.  If you don't know or understand what it is, it probably won't benefit you.  Some methods of rooting actually risk bricking your phone. (but most are proven to work) But if you really want to dig into it sometime let me know.

Must have apps:

My favorite app right now is Google+ which is the accompanying app to google's new social site to compete with facebook.  But there are tons of "must have" apps out there. Here is a list to start:

http://forum.androidcentral.com/htc-evo-4g/96061-must-have-apps.html

Itunes and Android:

Here's how to get your itunes music on to andorid:

http://www.androidcentral.com/how-sync-music-and-videos-your-computer-aka-itunes

When all else fails, google it.  Usually you'll find that someone else has failed in the same manner as you; their solution to the (your) problem usually follows.

Tips:

End a call with the power button:
If you head into Settings > Accessibility, hit Cancel if you get a pop window, and check the "Power Button Ends Call" setting, you can end it with the physical power button on your phone.
[Lifehacker]