Get a taxi as there is no metro.
The Airbus is fine from the Airport to the following points:
Entrecampos
Saldanha
Pombal
Restauradores
Rossio
Cais de Sodre.
Used it last week. € 3.00 per ticket
But then you still need to know how to get to your hotel and if it's up one of Lisbon´s hills you don't want to know about it with bags.