General Itinerary for Leh Trip:

1. From Delhi either you can travel through Manali or Srinagar. You take Manali route for onward journey and return thru Srinagar or vice-verse

2. From Manali or Srinagar its minimum 2 days trip. Can be done in 24 hours in one stretch, but doesn't make any sense for traveller :)

3. Make Leh as your base camp. Travelling around Ladakh can be briefly be drawn like star map with Leh in centre. There are four routes going out of Leh.

a) Leh - Tanglang La - Serchu - Rohtang Pass - Manali route

b) Leh - Changa La - Pangong - spangmik

c) Leh - Khardung La - Nubra Valley - Diskit - Hunder

d) Leh - Lamayuru - Kargil - Drass - Sonamarg - Srinagar

Route (a) and (d) can be covered when you get into and away from Leh. Reserve atleast 3 days each for onward and return trip. At least 2 days in Leh, and 2 days each for Route (b) and (c). So thats minimum 12 days iternary. If you got more time then spend more days at your places of interest and time for your favorite adventure activities like Rafting, trekking, Cycling.