First, check that your package is complete, compiles and runs well; see Debugging and the rest of this document. Then, generate a gzipped tar-file of all the files needed for the package, preferably with all files in a single directory. Place this tar-file to a place where the package maintainers can fetch it using FTP or HTTP (WWW). Finally, ``send-pr'' with category "pkg", a synopsis which includes the package name and version number, a short description of your package (contents of pkg/COMMENT are OK) and the URL of your tar-file.
You will be notified if your send-pr has been addressed so you can remove the tar-file.