Just accepted an offer for helpdesk–what can I do to excel?

I come from the educational technology side of things (K-12) with a great aptitude toward technology and problem solving. I'm moving into formal IT and am planning on testing for compTIA A+ at the end of the summer. What can I do at my job to make sure I'm doing well, excelling, and being seen by my managers, and not just slipping under the radar?