HowTo
Creating new packages
Creating new packages suitable for Ubuntu is not an easy process, and often requires knowledge of the underlying program or data to package.
Packages in Ubuntu are in the Debian .deb format, and hence can be created with standard Debian tools.
You might want to try to get your package in Debian as well, and not only in Ubuntu, so that more people will benefit from it!
Things to check first
Before you start creating a package, you should check for ongoing packaging efforts, or even for existing [http://www.debian.org/distrib/packages#search_packages Debian packages]. If the program you want to package has a homepage, look in the downloads section whether it already offers Debian packages. Search the mailing-list archives, ask the project, and in general search in all discussion channels of the project whether someone already prepared packages in the .deb format.
Check no-one started packaging the program already, and check for requests of packaging: the submitters of these requests might have started packaging the program already, or might have found another package source.
In Debian, packaging requests and packaging efforts are documented on the WNPP page at http://www.debian.org/devel/wnpp which has additional information on classifying such reports.
Tools and documentation
The Debian project offers a lot of documentation on how to create packages in its developers pages, at http://www.debian.org/devel/.
See [:MOTU/Packages/Packaging] too for some pointers.
["CategoryMOTU"]