Use fraps mate, download uTorrent then go to isohunt.com and look up fraps. Download the first one it shows. If you download fraps off of the fraps.com website, you can only have like... 5 minute videos.
Hmm looks quite unique in some way, how many people are you planning on having in your series? I'd love to be apart of it if I wasn't planning on doing it myself.
Hey mate, your videos could use a little work on. There's shaking in your latest video which you can get rid of in Video Manager I think. Other then that your videos are quite good and I like to see younger people playing Minecraft and enjoys making videos. Keep it up and goodluck!