As far as I know, in the outskirts of Lisbon, Guincho beach, is a very popular surfing place. You might try that.

Well you have many options when going to lisbon all of them u have to take the public transportation system, and can take about 1 hour to get to the surf spot depending where are u staying. I would advise 1 of 2 options to have a pleasant surf trip. 1. Stay near the train line (cais do sodre-cascais) the more near to cascais more beaches. Try Carcavelos Beach!
U can also get a bus to Praia Grande (Sintra) part of the WQS of bodyboard!
2. Stay in Caparica (south side of the River) u have tons of beaches there u can walk

any of these options have detailed swell information throw www.offshore.pt and www.beachcam.pt

goood waves!

I have surfed in Ericeira,50 km northeast of Lisbon. The beach and waves were great there.
It was also my first experience of surfing. It was like this;
Firstly, teacher told us how to get up on the board which we had to practice on land . After being given the instructions about safety, we took our boards and went to the sea.
I jumped on the board, waited for the wave, the teacher gave the sign which meant being ready to get up, I got up like I was told, 2 seconds of standing and I am in the water again. My record was 4 seconds! =)

If you look for somewhere closer to Lisbon,I suggest Carcavelos. My house was in Carcavelos, it is a calm place with a huge beach. Good place for surfing also but a bit crowded at the weekends.