Nancy,
We currently do not map this way here at the city, but here's a little advice, definitely get yourself a R1 Bluetooth receiver. A standalone tablet will not be accurate enough for sufficient mapping.
https://www.trimble.com/mappinggis/r1-gnss-receiver.aspx
Maybe contact Erin Fashoway at the Montana State Library, when she worked at MDT, she dealt a lot with the different tablets and could tell you lessons learned from the road inventory collection projects.