List possible interview questions, and then role-play with a friend or two or three to give you practice. Take turns being the interviewer. Bookstores and libraries have books that list every possible interview question one could ever think of.
If there are gaps in your job history (or even if there aren't) and you're putting together a resume, it might be a good idea to do what is called a skills-based or combination (chronological + functional) resume. The major part of the resume would be your skills and accomplishments with a section devoted to headings such as Customer Service or Management and Training, and under those headings list job responsibilities/achievements, like so --
PROFESSIONAL SKILLS AND EXPERIENCESUPERVISION AND TRAINING
* Train and motivate employees to meet and exceed company and customer service expectations
* Monitor the quality of employees' work to meet company guidelines
* Perform scheduling changes and updates, as needed
INVENTORY CONTROL AND WAREHOUSING
* Dealt with chemical operations, including the usage/storage/disposal of hazardous materials
* Inventoried finished products which included quality control, data entry, and data reporting
* Performed regular/year-end inventory checks of all machinery/raw materials/finished products
* Maintained factory equipment, operated forklifts, performed custodial duties CUSTOMER SERVICE
* Interact with clients/customers and listen to complaints
* Find solutions to operational or service problems
* Monitor operations to identify any future problems or misunderstandings
It's a good idea to do some research before applying to a company, so you can ask the questions that Joy suggested. At the library, look for annual reports, public or private company information, and other clues as to what they do and how they do it. Of course, for some companies there won't be much or any information, but the company may have a website to explore.