This can typically be done by thoroughly reading the job description and/or position vacancy announcement. Look at job duties, position requirements and preferences, desired traits, knowledge/skills/abilities (also called KSAs on governmental announcements), etc.
If you are developing your resume for a database or a class, not for a specific job, this step can be accomplished by gathering job descriptions/vacancy notices from various websites. Get 5-10 different notices or job descriptions and note the common traits and experiences sought. Don't worry about where these jobs are located. You're not really applying for them - you're just trying to get a feel for what employers are looking for in a successful candidate!
Follow this link to access websites which list jobs - note that they are organized based on major/career field. You can also log in to BuffJobs or look on larger boards such as CareerBuilder, etc. for help in finding descriptive job announcements.
Another terrific resource for occupational information is found in the O*NET, a governmental database maintained by the US Department of Labor which provides a exhaustive list of KSAs for a large number of occupations in the United States.
Our recommendation is to highlight or underline the Knowledge, Skills and Abilities (KSAs) in the job description(s). Use the worksheet "Job Description to Qualifications made Easy" to work through your match and fit for the career field and begin developing a qualifications section as well as highlighting possible job accomplishments.