1099 for Interior Decorator, Handyman, & other contractors work

How do the tax ramifications of a hiring people to do small jobs (but over $600/year) work? I’ve heard you’re supposed to file a 1099 with the IRS and provide a copy to the contractor if you’re the one paying for the work, but when is the best time to do that and how do I got about issuing it?

If a contractor’s work spreads across the two years, do I file the 1099 for the year of job completion? Do I need to file a separate 1099 for each year if a partial payment was made in the first year prior to project completion in the second year?