Closes #10888, #10889: Add supplementary notes to installation docs

docs/installation/3-netbox.md

@@ -272,7 +272,10 @@ See the [housekeeping documentation](../administration/housekeeping.md) for furt
 
 ## Test the Application
 
-At this point, we should be able to run NetBox's development server for testing. We can check by starting a development instance:
+At this point, we should be able to run NetBox's development server for testing. We can check by starting a development instance locally.
+
+!!! tip
+    Check that the Python virtual environment is still active before attempting to run the server.
 
 ```no-highlight
 python3 manage.py runserver 0.0.0.0:8000 --insecure

docs/installation/4-gunicorn.md

@@ -14,7 +14,10 @@ While the provided configuration should suffice for most initial installations,
 
 ## systemd Setup
 
-We'll use systemd to control both gunicorn and NetBox's background worker process. First, copy `contrib/netbox.service` and `contrib/netbox-rq.service` to the `/etc/systemd/system/` directory and reload the systemd daemon:
+We'll use systemd to control both gunicorn and NetBox's background worker process. First, copy `contrib/netbox.service` and `contrib/netbox-rq.service` to the `/etc/systemd/system/` directory and reload the systemd daemon.
+
+!!! warning "Check user & group assignment"
+    The stock service configuration files packaged with NetBox assume that the service will run with the `netbox` user and group names. If these differ on your installation, be sure to update the service files accordingly.
 
 ```no-highlight
 sudo cp -v /opt/netbox/contrib/*.service /etc/systemd/system/