I've built a package and it is in my PPA here https://launchpad.net/~evarlast/+archive/ppa
I searched a little and found this https://wiki.ubuntu.com/MOTU/GettingStarted but I could not find a simple howto guide on how to get this into universe.
The workflow for submitting your package is here:
and then keep an eye on the sponsorship queue:
I also recommend getting ahold of a MOTU to see if your package is appropriate for Debian as usually submitting to Debian and syncing back into Ubuntu might be a better way to work.