Q. What's the best way to track [agency] administrative jobs and activities?
A. First, add your agency as a Client. Then, open a job titled, "In-House Charges [month]" on the first day of each month. Record non-billable/non-recoverable time under said Number (e.g. Vacation, Sick/Personal, cleaning out the supply closet, etc.), as well as P.O.s for coffee and copy paper, for example. This becomes a monthly "catch-all" job for random expenses (and Tasks) that cannot be billed against a Client's job.
On the last day of the month, refer to the job's Financial Report and transfer applicable items to your accounting program. Lastly, close the job and open one for the next month.
You can also open other agency-related jobs within your Client folder (e.g. 2007 Christmas Party, Letterhead Re-Design, etc.).