First, you need the right tools. Second, you need qualified testers who need to be trained. Third, you need to invest time and effort in automation infrastructure and to develop tests on top of it. Developing automated tests is a software development effort itself. Tests need to be designed, coded, and validated before you can really put them to use. But the biggest effort comes just when you think you're done.
Worst case, your testers spend all day maintaining the automation false failures, adjusting the test code to match the current system, and rerunning them. This might have some marginal value, but it is incredibly expensive, and valuable only when the programmers are making changes that routinely cause real failure. But that's a problem you need to fix, not cover up with the Band-Aid of testing tools.
This article uses the term “tester” to refer to the person involved in testing software with automation tools. It is not meant to distinguish by job title or technical proficiency. Jim Hazen describes himself as a hybrid, or “technical tester,” because he can write test scripts and develop what he refers to as “testware.” The trend is to hire for multiple skillsets, but that does not mean the non-technical stakeholders involved in software development don’t benefit from automation testing.