A lot of the sort of reporting on the IT end of things that would normally be included in this sort of report assumes an enterprise environment with a large support department, so it would normally include things such as average time to response after a trouble ticket is opened, average time to completion, etc. These aren't really appropriate and indeed may be harmful in a small company with only one administrator: I have been a lone admin in a tiny company like that, and when the boss got his hands on some metrics like that from a huge company (I didn't provide them, he saw an article on it in a business magazine) he suddenly expected that I was single handedly going to provide the level of support that would have required me to be a 5 person team, and demanded I produce metrics to prove I was doing it.
All of that said, I would do one particular IT metric for management: a summary of support requests by category. Select the categories you feel are relevant, and then start tallying the calls. Usually mine include things like computer hardware broken, software needs configuration, software inadequate to task, new software requested, printer difficulties, new hardware requested, and EOBUE. The latter is "Error Occurred Between User's Ears", and I usually phrase it more politely on the report to management, something like "user difficulty". Sometimes I break it down further into things like "training needed" and "user wants admin to do work for them" if that's a significant problem.
Anyway, this report can be useful in several ways... if you're having a lot of hardware problems, it demonstrates that management should be investing more in replacing machines because they're costing downtime and admin time, so it helps you argue for a better IT budget. Same with software inadequate, or requests for new hardware or software. The EOBUE stuff helps you argue for two things: training for existing staff, and that computer skills should be part of hiring selection. Yes, I have worked with companies that didn't screen for this, and they consequently got a bunch of computer-phobic twits who were used to doing everything on paper and tried to get the IT department to perform their every interaction with the computer for them. By showing that these idjits were running the support group ragged with constant stupid requests, I was able to get the company to start asking applicants about their computer skills before hiring. And in another case, I was able to get the employer to send an entire department for training, after which they were told that they could no longer pester me to do their work for them because they were supposed to know how now.