You do not need to speak Portugese. In the Forum search box above put the poster name lobomau, and look at his posts. He lives in Lisbon and is very helpful.
We rented a car while in Portugal , picked it up in Lisbon and dropped it off in Porto; you do not want a car in the cities. Lots to explore between them. With so little time, perhaps taking the train between the cities is best if you do not want to explore the areas between them.

Car would be nice but I took trains and or buses to the following places you may consider hitting.

Lagos to Lisbon - excellent train service via Faro - a nice old town worth at least a brief look

Lisbon - be sure to day trip to nearby Sintra by commuter train - the old royal town on Portuguese royals - fancy palace in town and a sumptuous famous palace out of town on a hill surrounded by forests.

Heading north Obidos is one of the finest old ramparted towns I've ever seen in Europe - check out the Portuguese equivalent of Spain's Parador set in part right inside the ancient walls themselves.

Obidos to Coimbra (good train service Lison to Obidos and Obidos to Coimbra - check out Coimbra's upper town - the university district and its awesome architecture and main square - another good town to stay in.

Then en route to Porto stop by Albaca and Batalha - to see two famous ancient abbeys/monssteries ? - Batalha being especially famous.

I stayed in a sweet old fishing village and day trip to Batalha and Alcbaca from there but cannot recall the name of the town, which would make a great place to stay - locals frying fish for sales in little lanes in the old residential district.

Porto is on old-world city of your dreams - check out the Port wine wine houses lining the Duoro River - great tours.

There are some nice day trips from Porto as well - like to Braga and along the lovely Duoro River Valley.

Can easily do all by train and or bus or a nice drive as well.

Thanks so much! I need all the help I can get and this is great info!

We LOVED our 5-night stay in Lisbon. Check out my trip report.

I can highly recommend the Avenida Palace hotel.

http://www.fodors.com/community/europe/lisbon-europe-without-the-attitude-or-price-tag.cfm

You don't need to learn Portuguese but your food experiences will go much better if you bring a menu translator. Also be aware that pronunciations in Portuguese are often very far from what you might guess them to be, so be patient if people don't seem to understand you. If you need to buy train tickets or use a taxi, it is not a bad idea to write down what you need to show to the person trying to help you.

Porto and Lisbon are both rich and a bit complex. Both have gussied up central "tourist" areas that are actually a bit hokey and less interesting than the various neighborhoods just steps away that are not renovated for tourism. That's a long way of saying that you don't have very much time to explore either city fully, so I wouldn't leave on day trips to isolate tourist attractions outside the city. A better use of your short time might be to look in your guidebook for information about riding the trams in both cities. They snake through the town and show you the diversity of the cities.

Evora is a UNESCO World Heritage city that could also be included on a trip between Algarve and Lisbon - harder to do by public transit but I did it by taking a bus from Evora to a stop on the main train line Faro-Lisbon.

Evora a wonderful old old city surrounded by cork tree plantations!

Thanks everyone! Keep the suggestions coming!

Seems to me that you might be interested in a deal from pousadas.pt...Car rental and pousada nights..We did this and it was fantastic..check it out..All of the country is outstanding..Busacco area with peninsula war museum and battle sites and Busacco Palace Hotel all tiled in the public rooms..Areas as mentioned above..Natural park area south of Setubal along the coast..NO development allowed!!! Porto Cova, beautiful!!! Side roads to see quaint villages..Temple of Diana in Evora.. A car is NOT good in Lisbon or Porto but well worth the rental to see the country..Algarve is pretty touristy but awesome cliffs and beaches.. could go on and on..Have a wonderful trip..whatever you do and/or see will be just great..