After you secure a job, pay a visit to your boss. Click on the conversation piece actions Actions, then Get Raise. If your boss refuses, they will let you know which skills you need to improve. Gaining a point in your job's specific skill set will earn you a raise.
If you have already increased skill points, go ask for a raise after you accept a job offer!
Laboratory - Career: Biology - Boss: Anya
Corsican Bistro - Career: Culinary - Boss: Marcell
Town Hall - Career: Politics - Boss: Ruth
Quickmart - Career: Buisness - Boss: Bernie