
Depends on the role. For support it is important to learn the basics of Linux or Windows administration (whichever you are applying for.) There are a number of free courses that you can take to help you out with Linux through edx.org and other sites. Really though, be passionate about technology and willing to show it.
Actually have the skills and abilities listed in the position advertisement, because you will have to prove your knowledge during the interview process.
Learn the basics and show an ability to troubleshoot and speak to people
Help answer questions real people are asking about your company. Your answers will be 100% anonymous.
The person asking the question will be notified of your answer, and it will be posted publicly. Your identity will be kept private