The readme should note that you can run
$ [bundle exec] script/delayed_job run
$ [bundle exec] rake jobs:work
since the former is provided for free with daemons.
This is useful information, especially where one might want to cause the workers to be supervised by a process supervisor such as runit, which takes care of daemonizing your process for you (and expects you to give it a process that does not daemonize itself).
The readme does mention it under running jobs.
Closing, inactive. Submit a patch if you have strong feelings on the subject.