Jane Friedman’s key book publishing paths
There isn't a one-size-fits-all answer to the question of whether one should traditionally publish or self-publish.
So Jane Friedman has put together a comprehensive infographic that gives guidelines on who should choose traditional publishing, self-publishing/assisted publishing, and social publishing.
You can view the graphic on its own (plus download and distribute it), or you can read a text-only version on Friedman's blog.