By road
The National Highway 8 which runs through Rajasthan is excellent and connects Delhi to Mumbai. Though Mumbai may be too far away, this is the most popular way to travel to Jaipur from Delhi as the road is in excellent condition and the drive can easily be completed in under 4hrs.
By plane
Rajasthan is one of the larger Indian states and distances are long, making planes a fairly good option for getting in. Jaipur, Jodhpur and Udaipur all have airports with direct links to many major cities, though if coming from a smaller city, one has to go via Delhi.
By train
Overnight trains from Delhi and Mumbai reach most of Rajasthan's major cities. For points further out, like Jaisalmer, you'll be looking at a second day on the train as well. The Shatabdi and Rajdhani express are excellent trains and have excellent service.
Another option is Palace on Wheels which is a week long luxury train ride through Rajasthan.New Luxury train also started for rajasthan Named Royal rajsthan on wheels it is also a best option for travel royal rajasthan on wheels (http://www.royalsrajastha...)