First off let me say that your channel art is the BOMB! Really nice.
Not sure if this was only on the video I watched, but the intro was about 35 seconds long. I would recommend cutting that down to no more than 7 seconds - keep it short and sweet and to the point.
Your voice-overs have a very nice medium. You're not obnoxiously loud but you're not boring either - you're a great in between. You have a lot of potential on your hands and have the ability to blow up if you stay consistent.Just a few tips:
Try and avoid those awkward silences that you tend to have during certain parts of the video. It's not everywhere, but when it's present, it's noticeable. Talk about something - anything, it doesn't even need to relate to the video at all.The last tip is to try and project your voice when you can - remember, you are speaking with an audience, and even though you can edit your volume to make it louder, projecting your voice immerses your audience into your video more and makes it a lot more interesting.
Keep it up though!

You're doing great thus far!