When I exit SSH session bitcoind goes down I'm using Ubuntu 12.04. 

I've tested several scripts that try to get bitcoind running on startup but none have worked out for me.

I'm getting a little bit desperate because I can't even get bitcoind running once I exit my SSH session.

Any clues on how to get bitcoind running once I exit the SSH session?

Best Regards,
You could use screen or a similar tool like tmux or byoblu. 
Otherwise use the NOHUP command. 

nohup is a POSIX command to ignore the HUP (hangup) signal. The HUP signal is, by convention, the way a terminal warns dependent processes of logout.
Output that would normally go to the terminal goes to a file called nohup.out if it has not already been redirected.
nohup is a low-level utility simply configuring a command to ignore a signal. As seen below, nohup is very far from being a full-featured batch system solving all the problems of running programs asynchronously.


  $ nohup abcd &amp;
  
  $ exit


Alternatives:
The screen or tmux command can also detach a process from the current shell. It allows to reattach to the process later on.
e.g. the following call will run somescript.sh detached from SIGHUP and in the background:


  $ screen -A -m -d -S somename ./somescript.sh &amp;


https://en.wikipedia.org/wiki/Nohup

My advice is to learn to use screen (or tmux) so you can later re-attach the process to the main shell and interact with it.