This should be in the questions forum.
Every job has certain skills you need to do the job. It also has a difficulty rating.
You add up your skill points (only the ones needed to do the job...if one skill is there twice, double that rating), and get your total number.
You total skill points minus the difficulty of the job is how many labor points you have.
If you have less skill points, you will have negative labor points and be unable to do the job. You need at least one labor point to do the job.
To 'get labor points', first look at the job you need labor points for. See which skills are needed for the job and spend your skill and attribute points on those skills.