I was hoping for some more replies to this thread. I've had my eyes open for software to help manage maintenance on equipment, provide some instrumentation for a hot house and help plan/track the garden (not all in one).
A note about QGIS, I've used it along with some other GIS software. GIS software typically isn't friendly for normal users. You can get part of the way there by using google earth (GE). You can add your own data, import other data, use free aerial imagery (from different times), get directions, etc. You can expand it beyond your 'borders' too - I have a local real time weather layer and a power outage layer pulled into GE, so i can see how bad the coming storm is (w/ regards to power outages). You can definitely do a lot more with QGIS (and I do), but you don't need a 120 hp tractor to mow a 1/4 acre yard.
Keith