DB Design Questions

I am trying to build a db for the office I work at. And I have a few questions about how I should design it.

1. My vendor number should be an autonumber, but it has a relationship to the vendor name on a report. I cant create a relationship btwn text and autonumber.

2. Right now I have 3 main tables. Vendor, builder, and job. All of this is for the marketing aspect of the business. But I want to include other aspects, like collections and payroll. Should I add columns to the jobs table, or create a new table? For example, on the jobs table, I already have job info like details on the job and who referred it to us. Should I add invoiced amount, amount collected, etc., or create a table called collections to store all of this info? Im really confused about this.