To learn, humans have to imitate someone else. That's the way we process information and skills. It's really important to develop your own style and image once you've got the skill set, though.
I don't know much about cinematography. I will say that having a camera man often makes things way better than always doing a static shot on a tripod. But you start with what you have and work from there.
So pick a shot you want to create - whether you're coming up with it yourself or copying someone doesn't matter. Just know what it is you're creating. Frame it, shoot it, then shoot it again like 5 more times. Then you'll have lots of footage to work with. Always give a lead in of a few seconds before you actually start doing anything so you have extra footage to cut off if necessary. You can't add it in later, but you can cut it out easily.
Remember that After Effects is for creating clips - not whole movies. Generally I only end up making 1-10 second clips with AE then using Windows Movie Maker for patching the rest of the video together.
You can find all the tutorials you can hope for on YouTube and VideoCopilot.com if you have at least some idea of what you're after. You'll pick up the lingo as you go.
So, for example, the first thing I created was an outtro with my logo. I animated it so my logo "twitched" in, then "twitched" back out, then my name "twitched" in. (Twitch is a plugin from VideoCopilot - you've seen it, I guarantee it). That's maybe 5 seconds of animation. Took me two days to figure out how to make it all work correctly.
Then I took a few seconds of footage of a hypnosis session and mashed the two together. Twitch intro, video clip, my outtro. Done.
I feel it's important to have some consistency in your videos so I tend to use a similar format for all my videos. Certain types of transitions, sounds, etc. Oh yeah, sounds - you can find tons of them for free online so don't forget that.
Once you've uploaded it to YouTube you can use their Analytics to see a TON of information. You can see where people are watching the video geographically, where they found the video, what part of the video they are clicking off on, etc. So using that information you can judge which parts of your video need to be more interesting.
Of course, don't forget Steerpike's thread here called "How to Improve Your Videos Overnight". Lots of valuable information there.