There are a lot of things you have to worry about as an attorney at a small firm that go beyond the practice of law. If you have employees not only are you the attorney but also the manager and director of human resources as well. Why would you want to add payroll to that?
Luckily there are companies that will take care of that part for you and while it's not always necessary to outsource, this is one area where it might be a good choice.
Failing to properly account for payroll can result in lots of problems both from the IRS and from the other people in your office. So look around for a payroll service and keep these things in mind while you do.
Ask other attorneys. Not all payroll companies are created equal and some are better at helping attorneys with their payroll needs than others. Talk to other small firms near you to see who they use. That company might work for you as well.
Consider the billing structure. Some payroll services charge a flat fee but then ask for more if you hire other people. Others will change the same amount for up to a certain number of employees. Also check if the company charges more for cutting checks twice a month instead of once.
Customer service. The whole point of hiring a payroll service is so you have less to deal with. If calling the company to handle issues will waste hours of your time, that's a waste of your money too. When you find out the price take into account how much time you'll have to spend on the phone fixing payroll problems.
Other services provided. Payroll services often include other benefits such as tax paperwork, human resources, and additional help related to paychecks when you sign up. In bigger companies that may be included in a plan unless you request not to have it. Figure out what services you want and then find a company that can give it to you.
Liability for mistakes. Problems with payroll often translate to legal issues with the IRS. You know how to read the fine print so make sure it's not your firm on the line if the payroll company makes a mistake that ends up costing you in April. It's probably best to pass on a company that won't accept that.