In reply to tommytuffa:
A useful starting point is the commercial sector. Have a look at the websites of those like Jagged Globe, Alpine Ascents, Martin Moran, etc. see where they go, read their reports, look at their galleries. That might give you some inspiration on.
Another question is when you can go. There are places where the best time to visit is August, and there are places where August will be a nightmare. In very broad terms, the monsoon heads north for m India, and close to the border of what was Tibet the rain runs out and you find yourself in a desert. If you have the monsoon, then best to go before or after the monsoon (May or October should be good), but if you go to the desert areas, then mid summer gives you the warmest weather. But this is very broad terms.
The desert areas are very different from the areas that get the heavy monsoon rains. Again, in very broad terms, the desert areas are Buddhist with gompas, the wetter areas are Hindu with temples. Very broad terms. The desert areas have lots of bare ground and lots of irrigation, the monsoon areas are more forested, with deodar pines or rhododendrons depending upon area.
I recommend you look at
http://medex.org.uk//medex_book/english_version.php for excellent guidelines for altitude. This is a useful reference when planning your own itinerary, or when assessing commercial trips.