if you search for aa route planner this will give you all the info you are asking. You can go to and from any place and it works it all out for you - same as sat nav.
But occasionally you need to use common sense as well. As a trial I planned a route to the Isle of Wight via my favourite Southampton/East Cowes ferry instead of the Portsmouth/Ryde one. I put in Southampton and East Cowes as points on the route. It sent me to Southampton, then Portsmouth, then Ryde and finally back to East Cowes.