Permissions

By default, Jobs should grant the appropriate permissions to users out of the box.

You may also give permission for player like jobs.max.3, so they could take 3 jobs even if in generalConfig max jobs set to 2. You may also disable jobs in specific worlds with jobs.world.worldname: false, or disallow certain jobs with jobs.join.jobname: false

Permissions can be found in this page.

PermissionsEx

PEX IS UNSUPPORTED. USE AT YOUR OWN RISK. THIS IS INFORMATIONAL ONLY

If you want to use the built-in permission system in Jobs, you MUST turn strict-mode to false AND compatibility-mode to true in your PermissionsEx/config.yml.
I would recommend turning this off if you are having difficulty setting up permissions. The majority of issues is due to incorrect permissions.
If you don't understand any of this, just use the example below to turn off strict-mode and turn compatibility-mode on.

PermissionsEx/config.yml

permissions:
  backend: file
  backends:
    file:
      file: permissions.yml
  superperms:
    strict-mode: false
    compatibility-mode: true