Don't forget the non technicals...
Most people here are suggesting technical skills you might want to learn. That is certainly a good start but for your first support role I feel it is more important that you can show your future employer that have all the other qualities that make a good support agent.
I used to interview for 1st line helpdesk positions and 90% of the time we went for the person who had the better communication and troubleshooting abilities rather than techincal expertise. If you do get an interview, make sure you comunicate clearly and focus on your ability to provide the best possible service to your customers (the user base) and try not to portray yourself purely as a technical specialist.
Biting the hand that feeds IT
