Here is a basic workflow I used to get started
bzr branch lp:openracing trunk (put the default openracing branch which is our trunk into a directory called trunk)
bzr push bzr+ssh://firstname.lastname@example.org/~keithcu/openracing/work (This creates a remote branch on the server called work for you to work with)
Now you have to get it:
bzr branch lp:~keithcu/openracing/work
Party like crazy
bzr add (It will add your .hg directory if you aren't careful! bzr revert throws them away)
bzr commit -m "Party like it's 1929"
bzr push lp:~keithcu/openracing/work (to push your changes to the remote server -- not strictly necessary, but it lets others pull from them, and backs your changes up in case your computer dies.)
bzr merge ../work
bzr commit -m "Applying work to trunk"
Push changes to trunk so they are now in mainline
bzr push lp:openracing
To get your work branch up to date you can:
bzr merge lp:openracing
Here are some notes but they aren't that helpful because they don't assume launchpad http://doc.bazaar-vcs.org/latest/en/mini-tutorial/index.html