For train schedules in India see cleartrip.com or http://www.indianrailways.gov.in/ and for general train info see seat61.com.

Cleartrip is easier to use than the government site and doesn't bug you with pop-up windows. To answer your specific question, yes, there is a train. It leaves Delhi at 17:30 and is scheduled to arrive in Jaisalmer at 11:00 the next day. That train used to only have 3AC available, but I see that it now has 1AC and 2AC.

That doesn't look too rushed if you have three weeks. You need to lay it out with the travel times.

You might find this recent article from the NYT to be a helpful perspective.

travel.nytimes.com/2012/03/25/travel/through-indias-desert-cities-three-itineraries.html

Only if you're interested in luxury hotels, traveling everywhere by car and driver, and looking for shopping ops and western food. I thought the article was a travesty.

The perspective I found helpful was how much to fit into one trip in India. I don't think you have to stay in expensive hotels or shop to find this info helpful.

Three weeks is doable. Two might be a bit rushed. Up to you! Yes, there is a train. We usually catch the DLI/Jaisalmer train from station code DEE (Delhi S Rohilla) Station. It's about 5 kms from New Delhi Station. I believe the train originates at Old Delhi Station but you'll need to check on cleartrip.com. Just a warning re cleartrip...they are difficult to contact by email. They do not answer emails and they are even harder to get money from, imho! If you have the time and travel dates could change etc. then I'd book via Indian Railways own site. You can get refunds simply from the Govt site. A tip is to pay for a porter at the Station. It'll cost you around 20-30 rupees per bag (agree a price before you let them take your bags!) The porters know exactly where each carriage is located and you can hop on in the right carriage, far easier than searching for your seat yourself as the train stops for a few minutes only. Do not pay the porter until they deposit your luggage where you want it. This train is a wonderful way to experience India! At Jaisalmer the touts are awful. Just hold on to your bags and hope for the best! Best to book a pick up from your Hotel or Guesthouse.

Thanks for everyone's replies.

I had no trouble whatsoever getting refunds from the cleartip site when I canceled a couple of trains. They showed up without me ever asking. Much easier to use then the government site.

I have travelled several times on this route. It is a very slow moving train with at least three dozen stoppages enroute. It has never been on time and delays are over a couple of hours, on a few occasions!! The better option is to fly from Delhi to Jodhpur and drive on to Jaisalmer. You will be there around sunset. You could also stay overnight at Fort Pokharan if your sight is on medium hotels or you could stay at The Serai, which is short of Jaisalmer. The stay at The Serai is magical!
Happy travels!

If you are hiring a car service for any portion of your trip, the same agent you work with should be able to get you your train tickets. Arvind from Castle and King was most helpful and reliable in providing our car service as well as in helping us get train tickets which he delivered to our hotels. We liked the mixture of trains and cars for this trip.

To Anser the questiuon, the Delhi-Jaisalmer Express leaves (old) Delhi station at 17:30 and arrives Jaisalmer at 11:00 next day.

It has AC1, AC2, AC3, sleeper class. AC2 is the 'norm' for westerners, some backpackers swear by sleeper class (to basic for most), AC1 is twice the price of AC2 and not necessary unless you aren't worried about money.

1,262 rupees (about ($28) in AC2, 2,095 in AC1. You get a flat sleeping berth with bedding in both these classes.

I've put instructions for registering and buying tickets online at www.seat61.com/India.htm

We took this train 2AC at the end of February after overnighting in Delhi upon arrival in India. It is slow with many stops and seemed to be a noisy train so we were disturbed at night. But, it worked, and we got there. Jaisalmer is worth it. Don't eliminate this from your itinerary. And, don't only plan big cities; that is not what Rajasthan is all about.

Cleartrip is easy to use (and to cancel on). The only problem we had with the site was after we arrived in India and there was a requirement (from IndiaRail) that we also have an account with IndiaRail to coordinate with our Cleartrip account. This was a huge hassle because I kept getting error messages that we couldn't figure out what they were and couldn't correct them.

julies - that's very interesting - I didn't run into that. How did it come up?

I created a Cleartrip account before we left home and used it to book tickets. When we were in India and wanted to book some more tickets, I logged on to Cleartrip. I'd get part way into the booking when I'd get a message from Cleartrip that even though it is a hassle, IndiaRail required that I also register with them. This is where I had the major problem; I just couldn't get the IndiaRail part to take my info. This went on for several days.

One day I decided to try to get around this issue by trying to use MakeMyTrip. I got the same message from their website, but here I finally was able to get the IndiaRail part registered and coordinated with MakeMyTrip. Finally! I thought I would be able to now book. No such luck because I got all of the way to the end and got the response that non-Indian credit cards weren't accepted. So, that was the end of that idea. I don't know if it will work or not, but my suggestion to people who want to use MakeMyTrip would be to establish an account in your home country before you get to India. That way your "foreigner" credit card number will already be in the system. I am just guessing this would work.

After three days of trying (and swearing at the computer) I finally got the IndiaRail part of Cleartrip to take and was able to buy tickets. I also heard from other tourists while we were in India that they had encountered the same problem with cleartrip, and an additional issue is that the IndiaRail part requires a mobile phone number in order to register.

How annoying. Must be a new thing, as I didn't run into that at the end of 2010.