Transport and itinerary help

Sorry, Maggie but your itinerary is a little vague. I suggest you get a little more specific on your cities, and look up "multi city" flights in Kayak.com. Flying open jaw into one city and out of another prevents expensive back tracking. However your detour over to Denmark will prove to be very costly due to a lack of budget flights. It's also a generally expensive country. Munich would probably be a good place to base Germany and Austria travels from, and the city has good rail connections. When you get to your destination cities, you could always rent a car to see the countryside.
Munich would also be a good place to fly out of.

If you are going to be in Ireland for 10 days then you have just 11 days for 4 countries including transport. Not very realistic. To get to Ireland there is a direct flight from Seattle to London. There are plenty of flights to Dublin from there. I would use open jaw and fly back from Frankfurt to Seattle which would be direct flight, too. If you look at the map you would see that realistic travel plans could be Ireland, Germany and one more country. The easiest one based on your presumed departure point seems to be Switzerland. You can get around Germany, Switzerland and Austria by train very well. In Ireland not too many options by train. Either bus or car. Denmark has more train connections than Ireland and less than Germany or Switzerland. If you plan just to be in big cities use train. For countryside rent a car.

Thank you both! We are visiting friends in those countries. Only going to Copenhagen just one nigh to visit our former exchange students. Will skip Austria. Distant relatives in Germany and Close friends in Zurich. Trip was originally to go to Ireland again- but it's taken 10 years to get back. So thought we'd better see people while there! Thanks for your help! M

Does your three weeks include your arrival and departure days? If so, you will essentially lose two days of your 21 days just getting there and back (you arrive the day after you leave home, and your departure day won't be useful for anything but getting to the airport). You also need to look at the travel time it takes to get from one place to another, and remember you also need to spend time doing things like packing/unpacking, waiting for the plane/train, security (if you use cheap flights in between), getting oriented in your new location, checking into your hotel, etc. You can expect to lose a half-day or more every time you change cities. It might be helpful to you to look at the distances between places at www.viamichelin.com.

Check Tripadvisor.com for the best deals on flights. I found flights are cheaper to buy on Wed and Thurs. My friend just saved $300 on a multi-flight for Europe by waiting to buy it on a Wed.