Drawing maps on google maps for a charity walk

My name is Laurence Carter. I'm a 57-year-old Englishman living in Washington DC. Two years ago my wife died of cervical cancer. To honour her memory, and to spread the word that cervical cancer is a preventable disease, and to raise some money for cervical cancer research, I will be starting a one year walk around England and Wales this June. I aim to complete the 3,500 odd miles within a year, walking most days, averaging 10-12 miles a day. The task: I have a spreadsheet with start and end points for each walk, together with approximate distances. This spreadsheet needs expanding. Each walk needs to be drawn on Google maps (using the route closest to the sea, and using bridges, not ferries, to cross rivers). That map needs to be saved and a link put in the spreadsheet, for each leg. The exact start and end points need to be put onto the spreadsheet. And the vertical distances up and down need to be put on the spreadsheet. All of this can be done via Google maps, I believe. I could pay by the hour, or for each leg for which the information is completed. There will be around 350 legs, although so far the spreadsheet only has about 50 legs inserted.