Madrid to Barcelona by way of Toledo, Granada,Seville and Cordoba

Hmmm...my suggestion:

Leave Madrid, to Toledo. 1 night, if you get an early train out (so say arrive at 10AM, leave the next morning). This could be 2 nights easily, if you want to minimize 1 night stops. A lot of people do Toledo as a day trip from Madrid and the highlights can be seen in a day but you want to enjoy the PM atmosphere.

Train from Toledo back to Madrid, switch to a train to Granada. This is a slower train, I put Granada 2nd because it's not on high speed rail so it is the hardest to get to Barcelona. So not a place to end. 3 nights.

Train or bus to Cordoba. 2 nights. Bus might be easier. Can be done in 1 night if you arrive early and/or leave later and just want to see the Mesquita. But to see other things and enjoy the town...2 nights.

Train to Seville. 3-4 nights.

Train to Barcelona.

Note that from any of these you can stay longer and do day trips! The days I listed are for seeing the main highlights of the town itself. All are great towns and could benefit from time to just "hang out", too.

Have not been to Granada so can not comment on it. Toledo is 1/2 by AVE from Atocha Station in Madrid...The one and only stop on the line..I recommend two nights there..it is a different place in the late afternoon and evening when the day trippers have left. Posada De Manolo is an excellent Hostal by the Cathedral and includes a great breakfast overlooking the Cathedral.

Sevilla, and Cordoba are on the same train line. Sevilla is about 2 1/2 hours and Cordoba is shortly less. You can not just get off the train in Cordoba and continue on to Sevilla...separate tickets are required. Cordoba is good for two nights. Sevilla for three I think. Really Discover Sevilla has a great selection of tours and they are smaller groups than the larger tour companies there. Also, they can get you connected for tickets for a great flamenco show. The train for Sevilla and Cordoba also leaves from the Atocha station. It does have a food car on it (light snacks, etc) look for it as your board. On the trains the tickets will have the car number and the seat number printed on them. Deposit your luggage in the bins as you enter the car. A great ride for sure.

Since you seem to have plenty of time, I would mostly concur with the above recommendations. Toledo should be 2 nights as you can spend more time exploring the city and sites not as popular with the daytrippers. There are several Jewish synagogues and a former mosque (now a church) that provide a great insight into the layers of culture, religion and history in Toledo. There is a pass that gets you into pretty much all sites and worth it with 2 nights and visiting those I mention in addition to the other popular ones.

Toledo is at the end of a short AVE line, so you have to backtrack to Madrid but it's only 30 minutes. Then take a train to Granada. Currently the train transfers to a bus outside the city due to track construction, but it reportedly all works smoothly. You'll want 2-3 nights in Granada. Make sure to buy Alhambra tickets in advance as they sell out. With a few nights there try a nighttime visit too.

Then bus or train to Sevilla for 3 nights. Be sure to catch one or more flamenco shows.

Cordoba is along the AVE line between Sevilla and Madrid so it makes sense to stop there last and spend a couple nights. Like Toledo, a charming city when not crowded with daytrippers.

Then AVE on to Barcelona. You may need to transfer trains in Madrid.

Railpasses are not cost effective anymore. You can get deep discounts with advance purchases from RENFE (use Paypal to buy them, US credit cards often do not work). I believe you may also be eligible for a senior discount. Others may be able to comment on that.

A sidenote: Are you aware of the Schengen tourist visa rules that limit personal travel in most of Europe to 90 days within every 180 days? Without a residency visa, you will not be allowed to stay 6 months.

I have thrown Ronda into the mix as well.
It seems you have the luxury of time so you may wish to linger longer than the minimums recommended below.

Fly in to Madrid - 8 nights
Train to Toledo - 2 nights
Train to Cordoba - 2 nights
Train to Sevilla - 4 nights
Train to Ronda - 2 nights
Train to Granada - 3 nights
Fly to Barcelona - 1 month (www.vueling.com)

First of all, please, please tell us that you know all about the Schengen rules! For instance, if you are traveling on a US passport and arrive in Madrid with a round-trip plane ticket departing 6 months later from another Schengen area airport, you may be denied entry into Spain, unless you have a previously-obtained visa permitting a stay over 90 days.

Now that that's out of the way, on to Spain. Rail passes rarely make sense. You can buy train tickets about 3 months in advance at huge discounts. Since you are over 60, you can buy a one-year Tarjeta Dorada (gold card) which gets you a 25% discount off full price on weekend trains (Fri-Sun) and 40% the rest of the week, if you want to be flexible. You can only buy the card in person in Spain. Read this for the very best article on trains in Spain, it's everything you need to know.

I like David's itinerary best. I don't know how much time you have for Andalusia, but you could easily spend 2-3 weeks there after Madrid and before Barcelona.

A couple of train tips (I was just in Spain in September):

For buying tickets on Renfe's website, Chani's link to the TripAdvisor article is invaluable. If you buy tickets with PayPal, the transaction goes smoothly; if you try using a US credit card, it doesn't.

If you are taking a train from Toledo to anywhere but Madrid, you'll have to change in Madrid. To find all your options, look on the Bahn (German Rail) website http://reiseauskunft.bahn.de/bin/query.exe/en, following Rick's tutorial: http://www.ricksteves.com/travel-tips/transportation/trains/online-schedules. For some reason, when I tried to book Toledo to Barcelona on Renfe, it only showed two connections all day, but Bahn showed me that there were many more. I had to book the ticket as two separate segments (Toledo to Madrid and Madrid to Barcelona).

Some tickets have a small discount for round trips (Madrid to Toledo is one). But the real discount is for advance purchase of non-refundable tickets. If you can commit, you can save a bundle.

Trains from Madrid Atocha station leave from two different levels. If you are changing trains in Madrid and have to change levels, you don't have to leave the secure area. Ask for the elevator that connects the secure lounges (it's near the high number tracks). If you don't take this elevator, you'll have to go through the security line again (as well as taking a very roundabout way through the station to get there).

I found Madrid Atocha station confusing to get through - and I'm used to New York Penn Station. Allow plenty of time before your train departs. You don't go through a metal detector, but you do show your tickets and your bags are X-rayed before you get to the platforms.

On a non-train note, I liked Madrid more than some others seem to. Eight nights there would allow multiple visits to the Prado, among other things. And do be sure to walk around various neighborhoods, to get a feel for how different they are. Salamanca is rich and groomed, Chueca is gay, and La Latina is Bangladeshi and hipster - and all of these are a decent walk or short metro ride from Puerta del Sol.

At 62, you can buy a senior pass/card for Spanish rail that gets you a walk up fare discount of 25% for weekend travel and 40% for week day. I know some people became irritated when the Schengen zone guestion gets ask, BUT --- do you understand the Schengen zone limited of 90 days for every 180 days cycle? You cannot just park in Europe for six month without a special visa. And that visa can be difficult to obtain with all the hoops you have to jump through.

How many nights is a difficult, if not impossible question, simply because of personal preference. The question implies that there is some magically number of days for each city. There is not. It just depends. For some, a week in Seville is not enough and for others way too much. As a starter for us, we always plan two to three complete days. If there is more to see we added it to the list for the return visit. For the cities you mentioned, except Cordoba, that would be a good starting point. You can see about everything in one full day or two nights. Also, it good to think in turns of nights. Two nights somewhere really means one full day.