I need some advice on how to get from Madrid on September 14 to Oporto, Portugal via train or bus. Can anyone help?

Thanks!

....There is an overnight train Madrid-Lisbon(Lisboa) and then there are frequent( about hourly) trains Lisbon-Porto(Oporto). If you do not want to actually go to Lisbon i think one can change trains at Entroncanmento but i am not sure of this.

Some links:
http://www.portugal-info.net/travel/transport.htm
www.renfe.com
www.cp.pt

Enjoy your trip!!

There's a Bus line (check www.eurolines.com ) that does a day and an overnight run: costs 43 Euro - somewhat less than the train.