Originally Posted by
caspritz78
No need to buy the tickets in advanced. There are ticket machines at the train stations for the local trains from CGN to the city. For your trip from Cologne to Düsseldorf you can either take a local train (takes long) or a long distance train (IC, EC or ICE). I would take the long distance train and get ticket from the ticket machine or the internet. To look up the schedule and buy a ticket get on
www.bahn.de.
I partly disagree. No need to by a IC, EC or ICE ticket. They use the same routing, just make three stops less, actually saving is maybe 10 minutes.
Take a so called "Regionalexpress", abbreviated RE. They have the same fare as the so called "S-Bahn" that stops everywhere (like 20 stops on the way) but the RE just stops 4 times in between Cologne and Dusseldorf. That's not too bad. The RE trains usually leave from track 1,2 or 4 in Cologne. (depending of time of day)
Unfortunately, I can't really recommend a hotel in DUS. Are you with a particular chain? I would just try and get one downtown that suits your budget/preference and either take the taxi in the morning to the airport or the public transportation.