Where to start your camino?

You can start the camino from all places to Santiago de Compostela. Santiago de Compostela is located in north-west Spain.
See also http://www.caminosantiago.org/cpperegrino/caminos/mapa.html
I have decided to start from Porto in Portugal.
The rule is that you have at least a way to go of 100 km walking or horse riding or at least a way of 200 km cycling. My start is in beautiful Porto and I am going to walk to Santiago de Compostela. On the last 100 km (or in case of cycling 200 km) you need to collect two stamps per day in your pilgrim's pass to prove that you have made it. Only then you will receive the Compostela in Santiago de Compostela.
Every 100 years the Francistern order produces their own 'Compostela' to celebrate the Pilgrimage of Saint Francis of Assisi to Santiago de Compostela which happened in 1214 - 800 years ago - and so this certificate is available this year (and then there won't be another until 2114 J). To get this special certificate you need to take your credential to the Francistern Church between 10:00-11:00 hrs or 17:00-19:00 hrs (address: Rúa do Campiño de San Francisco nr. 3). Once inside go down the left hand side of the Church to the big wooden doors where there is a monk at a desk who will check your credential, stamp it and get you to fill in a simple form with your name, age and a few other details before he fills in your certificate and gives it to you (they do ask for a small donation). Addres: Convento de San Francisco, Rúa dos Castiñeiros in Santiago de Compostela, a bit further than the San Francisco Hotel coming from the cathedral.

On your camino you are passing many old roads from the Roman time.
On http://www.omnesviae.org/nl/ you can see that many roads are similar as the camino roads of today!