I'm in the process of dividing my layers into 'operational' and 'cached basemaps'. I've mostly been following the advice given in this white paper located here even though it's kind of old now: http://www.esri.com/library/whitepapers/pdfs/creating-arcgisserver-web-mapping.pdf
The one thing I'm confused about is how to enable users to 'Identify' parcels if they are part of a custom cached basemap. Should I have a parcel data point layer in my operational service? I would like for users to click on a parcel and get information such as owner name, legal description, ect. Was wondering how most people handle this. Trying to avoid having parcel data (which can be quite large) as an operational layer.
You can have the parcel layer in a map service turned off, and still reference the layer in your web map in order to display the parcel information in a popup or info window.