Calais to Spain? can anyone hlp with routes?

[cartaya]

Hi, im new to this forum and was wondering if anyone can help me out? Next spring I am looking to get the ferry from the UK and cycle down to southern Spain. Ive heard that going through France is best to stick to the west? I dont have any information on going through Spain. Does anyone know of any good routes I can take whilst camping along the way? Any help will be gratefully recieved,
many thanks.:)