Links 
Interactive Map
Somerset County Council maintain an excellent map of Somerset which enlarges down to house level. It displays all Public Rights of Way, with identifying codes - Wellington parish codes mostly start with WG17/.

Downsides: are a small active 'phone window and no GPS. Still indispensable.
Google Somerset roam or go here:

https://roam.somerset.gov.uk/roam/map

'Walkwell in Taunton and Wellington'  provides a twice weekly programme of short and long walks in guided groups, is free, and well supported. Part of the national Walking for Health:
 
http://www.walkwellwithtone.btck.co.uk/Programmes

Somerset Wildlife Trust suggest a variety of walks on their many reserves:

http://www.somersetwildlife.org/wildwalks.html

Grand Western Canal: Information on this beautiful canal stretching from Wellington to Tiverton:

https://new.devon.gov.uk/grandwesterncanal/visitors

Ramblers organisation publishes an informative guide on walking in the countryside:

http://www.ramblers.org.uk/advice.aspx