En español | More than a third of American companies are hiring contract or temporary workers this year, according to a survey of more than 3,000 hiring managers and human resource professionals by CareerBuilder and Harris Interactive.

Taking on temporary workers can save a fast-growing small business from overstaffing while testing out future employees, says Gwenn Rosener, a founder of Flexforce Professionals, a recruiting and staffing company in the Washington, D.C., area.

See also: 5 jobs in demand for 2013.

The work can be an attractive option if you're retired and need extra money. If you're employed and looking to switch careers or land a new position, contract work allows you to try out a job and keep your résumé alive at the same time.

If you're looking for a full-time job with benefits, that might be hard to find these days. But contract work could lead to full-time employment, so think of it as an opportunity to impress.

Firms like Flexforce place college-educated workers with 10-plus years of professional experience who are willing to work between 10 and 30 hours a week and want flexible work schedules.

If that schedule appeals to you, here are five small-business jobs you might consider. Rosener says these jobs "require special knowledge or expertise that the [small business] owners don't have, nor have the time to learn."

Pay ranges, which will vary based on factors such as experience and where you live, are primarily derived from U.S. Department of Labor data. For more salary examples, check out the Bureau of Labor Statistics' "Occupational Outlook Handbook."

1. Bookkeeping and accounting

The nitty-gritty: Jump into this one with eyes wide open and a sharp pencil. Owners have usually been doing this job, but then they discover they're snowed under and need to concentrate on building the business. You're likely to confront a backlog of bills to be paid, bank accounts to be reconciled and so forth. Chances are, there's not a proper ledger or accounting system in place either. Typically, bookkeeping or accounting positions start off part time (as little as one or two days a month) and then gradually expand into more of a commitment if the business grows.

Median pay: $16.36 per hour; $25 to $35 per hour for basic bookkeeping skills; CPAs or jobs at the controller/CFO levels are generally paid $45 to $70 per hour.

Qualifications: For accounting work, an accounting degree is usually required. A certified public accountant (CPA) certification is best. Knowing how to use the software package QuickBooks is often a requirement for smaller businesses. The American Institute of Professional Bookkeepers offers a bookkeeper certification, as does the National Association of Certified Public Bookkeepers. Community colleges and universities in your area are good places to look for continuing education offerings.

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