where/how to travel HP:May-Aug

Hot Tomali

Hi,

We're going to Mcleod Ganj for yoga from May to Aug. Also we want to do some travelling and trekking around HP. Manali, Kullu, Lahaul, Spiti, Kaza, Kinnaur, Chmaba, etc. I want to go to Ladakh in Aug as my mother(60 yr old) is coming from Korea to join us.
1. Can you suggest a good route to travel around HP to cover most of places worth visiting in May? Will I travel by bus? Should I travel from Mcleod Ganj? or should I go fro Delhi?
2. Trekking seems very expensive, so I will have to choose only one or two. Which one do you recommend? Which one is the most spectacular? We might not be able to do too vigorous trekking (considering my mother's age)
3. For August, where else can my mom visit except Leh? Can you suggest an itineary for my mom for the month of Aug? At this moment, we're just planning to visit Leh and do some trekking around Leh. But it seems trekking routes in Ladakh are quite hard(for my mom). Manali, Lahaul and Kinnaur,ect those places would be too wet?
4. For trekking in these regions, how cold does it get at night? What should I bring from home: down jacket? hiking boots?

Any help would be really appreciated! Thanks.