I decided to post some websites & info I found re: Sintra, as its kind of confusing on all the info.
this is the stops for the 434 bus that you take as you exit the train station to go to the castles and city center
This is the website for Sintra, with much information, including maps & what to visit, info on transportation, etc
This is the website for the bus company Scotturb...click on the "Percusos Turisticos" and you'll get a list of all the buses with all the stops they make...then you can click "consultar" and a screen will open with the time table and stops.
Hope this helps,