Ubuntu doesn't allow upload of binary packages, but only source packages which are build by build servers.
Getting your packages directly in Ubuntu repositories is not so easy. It is recommended to have it first in Debian and get it synced from there. So for now you can put it there in your PPA. You can create a PPA with your Launchpad account.
Uploading to PPA
If you used
debuild to build the package, then your work is a bit more easier.
debuild generates many files including .dsc and .changes
You might have used
.dsc file with
pbuilder-dist to create the deb file, so now all you need to do is to publish it to a PPA for now. Use
dput ppa:yourlaunchpadusername/ppaname foo.changes
You will need to sign the package before upload with the same key as you have uploaded in your Launchpad Account
Pushing in Debian/Ubuntu
The pushing of your package in Ubuntu/Debian repositories includes a review from the maintainer and the ftp masters at Debian. The license has to be very clear with no ambiguity. You might need a sponsor for uploading to Debian
Filing an ITP
You might need to file an ITP (Intend to package) to get it packaged in Debian. This is just a formal procedure.
When the package is available in experimental/unstable then you can use
requestsync tool to file a sync request on LP. For getting
requestsync working you need to run
manage-credentials to login to Launchpad
Both of these tools are in package