The only real route from Estoril from Lisbon Airport by public transport is as follows:
- Aerobus service from outside Lisbon Airport arrivals hall to Cais de Sodre station. First bus leaves at 07:00:
See: http://bit.ly/9b2Ga3
- From Cais de Sodre Station, you would then have to get a train to Estoril which takes about 30 minutes, depending on time of day/week/night.
Estoril is the second last station on the Linha da Cascais suburban railway that runs from Cais de Sodre in downtown Lisbon to the town/suburb Cascais.
Trains run between every 15 minutes to every 30 minutes depending on the day/time of week/day/night.
Trains start at 05:30 and run till 01:30.
Note there are some trains that terminate at Oeiras half way to Estoril. Make sure you get on the one for Estoril.
There are no direct bus services. The alternatives would be airport transfer or taxi.
This company, among others, provides airport transfer services from Lisbon Airport:
http://bit.ly/alg5sn
