Google ‘Free Airport Diagrams’, there are quite a few. The airport diagram will show taxiways, runways, and other general areas/info for your dep./dest. This is the ‘old school’ method and does required a bit of interpreting your position and visualizing (i.e. thinking 
) about how to get where you want to go.
There are also the same type of charts for Gate and Parking locations as well (at larger airports).
As mentioned Little Nav Map is great because (one, it’s free) and two, it will show your position in relation to the airport as you taxi/fly.