There are some very brief but adequate instructions here:
Mango is just a Java application, so the actual 'install' of Mango consists simply extracting files from a .zip file into a directory of your choosing. That's it!
What you are probably asking for is a step by step guide to installing Ubuntu and the Java JVM, which are both products NOT made by serotonin software, which is why you won't find an install guide! :-)
Otherwise Serotonin would have to make a million guides for every different possible system configuration that anyone might want.
I would suggest that if you need a step by step guide, try searching for these things:
*"How to install Ubuntu 13.10 server"
"How to install JDK6 on Ubuntu 13.10 server"
"How to unzip file in ubuntu"
"How to run .sh file on startup in ubuntu"
You could even make a note of the steps you follow and post them here to help others in future.