There are two means by which you can get from Lisbon to Evora:
1) Train (as already mentioned)
Departs: Lisbon Gare Oriente: 08:10
Departs: Lisbon Entrecampos: 08:21
Arr: Evora 10:07
Departs: Lisbon Gare Oriente: 14:10
Departs: Lisbon Entrecampos: 14:21
Arr: Evora 16:05
Departs: Lisbon Gare Oriente: 18:10
Departs: Lisbon Entrecampos: 18:21
Arr: Evora 20:14
These refer to the summer 2008 timetables.
Tickets can be booked online (sometimes) at www.cp.pt.
The only problem with the train is that you will then have to find your way from Evora Station to Evora Bus Station which is a bit of a hoof.
2) Bus
Rede Expressos - http://www.rede-expressos.pt/0010.asp - operate regularly between Lisbon Sete Rios Bus Station and Evora.
There are departures regularly throughout the day every 60 to 90 minutes between 07:00 and 22:00. Transit time is about 105 minutes.
You cannot book these online.
Evora to Viana de Alentejo
According to the local Council, buses only run on this route Mondays to Fridays.
See:
http://www.cm-vianadoalentejo.pt/pt/conteudos/informacoes+uteis/transportes/
Operated by Rodoviária do Alentejo - Line 8146
Departures from Évora: 07h15 - 17h30 - 19h15
Departures from Viana: 06h49 - 08h10 - 19h55
Services depart from Evora Bus Station
