For the first step "Building the Toolchain" quite intensive ruby knowledge is assumed. But ruby is kind of uncommon on Linux systems. So doing the first step can be difficult already.
I've searched the web and found that I have to install the package ruby-full in version 1.8 on my Ubuntu 12.04 system. But I've hit more dependency problems. I had to install ruby-hpricot, ruby-sqlite3 and then it complained about missing mahoro and I have no idea how to install that on my system.
There is really important documentation missing.