There are daily flights to and from here from Delhi. Alternatively, if you're launching from Leh, it's possible to fly to Srinagar and take bus to Leh to get a taste of the height and see the type of road you’ll be driving.
You can get a bus or flight between here and Delhi. Alternatively nearby Chandigarh has good and cheap flight connections with Delhi and from here it's a couple of hours on the bus. Flights to Shimla can often get cancelled due to weather.
It's advisable to get there a couple of days early to get used to the altitude.