What you can't miss is the Parque das NaÃ§Ãµes ( http://www.parquedasnacoes.pt/
). is a really good exemple of something that was planned and construted very fast, and might be seen as the city's architectural ex-libris now. (but the web site is not graet). The process was amazing and i have to tell you that we were very lucky with the result. I also think that Parque das NaÃ§Ãµes schould be a case study for all who are involded in Dublin Docklands area (housing, offices, urban design, sustanainable arch., etc.).
On this area you can fins buildings desigined by TomÃ¡s Taveira, Alvaro Siza, Souto Moura, etc. and an irish pub with decent guinness pints.
The Colombo Center and Vasco da Gama are good exemples of huge shopping centers but going there just to have lunch might not be best choice... try to stay in the downtown and go to the small but lovely restaurants.
Anyway if you go to Colombo shopping center you can see, on the other side of the road, the Eusebio statue, the old Luz Stadium (120 000 places!!) and the constrution site of the new one...
You can also visit the site construction of "Sporting Clube Portugal" Stadium about 3Km away from this last one. This Stadium is going to be open in August this year, wich means you can already "see" a lot. The project is very controversal, colorfull and very diferent from Siza's work ie.
see more about the stadiums at Paul's online pool at http://www.archiseek.com/content/showthread.php?s=&postid=8999#post8999
Another suggestion: a trip on the subway would be nice because all our subway stations were build or re-build on the last 3 years by our "best" architects like Siza (Chiado station), TomÃ¡s Taveira (Olaias station), etc. All stations also include art works made by famous portuguese designers and artists.
The site http://www.metrolisboa.pt/index_uk.htm
will give you a help on the paths and the stations. Again... the web sites are not great.
A ticket to see all stations = 0.55 Euros
You schould also spend some time at the downtown to see a urban plan designed by MarquÃªs de Pombal and built right after the 1755 earthquake that was considered to "modern" for the time. Still is a very active area and it's design supports the comtemporaneus traffic. Walk to the castle (S. Jorge Castle) where you find one of the best views all over Lisbon, Tagus River and South Lisbon (at the south part of the river).
If you like to go out at night visit the "Lux" night club wich is, in my opinion, the best club in town. Try to get in there at around 1 or 2am and get ready to get out at 6 or 7am. The interior design is great and all furtinure elements are replicas of real pieces they have for salling, made by famous international designers. The people and music are great too.
As for books I recommend you the "Lisbon-a guide to recent architecture" (one of those small silver books of the ellipsis collection).
This book is quite recent (1999), published after the 98 world expo, and I think you can find there good informations about Lisbon's architectural exemples their context. Also they are easy to carry around. Make sure you buy the last edition...
If you need any more specific information like nightlife, prices, where to stay and eat, you are welcome to ask again.
Also whatch carefully the weather report before you come because our country isn't always warm