I Was Too Bold! - Minecraft Gameplay from a Newbie

We're heading down in to the tower to find what lies beneath! And we were not disappointed! There is an entire cavern full of mobs and interesting looking platforms to explore below so we make our way down the ladders to check it out. Alas, like Icarus, I flew too close to the sun and...got too bold. As usual.
Please feel free to comment tips and tricks below to take me from total noob to...slightly more competent!
Map is available at:
www.minecraftm...