looking for your advices

Hi!
I’m an Italian guy that is planning his holiday/experience in India and I’m looking forward to receive suggestions from you…. The plan is to be in India 21 days ( maybe 28 ) anyway the plan right now is done according to stay on holiday 21 days (18.12.2010 to 8.01.2011).In case I will do 7 days more I’d love to visit Kumbh Mela.
Once in India I’d like to travel by bus and by train and I wouldn’t like to spend to much for accommodations.
During my researches I found an advice that I sometime forget to bear in mind…. Not to be over ambitious and try to see everything in a short time in a single trip instead enjoy calmly every place with peace of mind, so that the memories remain for long.
Before to deep in research I’ m trying to find some suggestions according to my plan that you can find below. (Obviously is not precisely detailed yet.)
DELHI -> JAIPUR  (250-300 KM)
JAIPUR -> Fatehpur Sikri (200-250 KM)
Fatehpur Sikri -> Agra ( 40 km)
Agra -> Gwalior (150 km)
Gwalior  -> Orchha (120 km)
Orchha -> khajuraho (175 -200 km)
Khajuraho -> Varanasi  (400 km)
Varanasi   -> Kolkata (750 – 800 km)

I would also love to see Himalaya and its landscapes….maybe you can suggest me a place to add at my trip unless you think I would have not enough time according to all the places I want to visit….Otherwise, according to your experience, you might suggest me not to see a place that I chose in my plan in order to visit some beautiful place near Himalaya!
I would very happy if you could suggest me anything that could be useful for my first experience!
I’m looking forward to receiving news from you!
Thanks a lot
Andrea