Reading / Maps
There are lots of maps and guides to use on the South West Coast Path, and more are being written all the time.
If you are from the South West you may already have several of the OS landranger maps for the coastline near you, but starting off carrying all the maps would be unnecessary weight.
I can highly recommend the Harvey maps series and the newer SWCP National Trail guides. I used the Cicerone South West Coast Path book by Paddy Dillon for much of the way and found it excellent (if a little heavy).