To start with, you should have 10 days at least to do justice to your vacation.But i understand the leave crisis we all experience at our workplaces and therefore shall give you a list of touristy things or places to visit while the non touristy things as well. You could incorporate it in your itinerary according to your interests and time available.
I shall make an eight days Itinerary with:
2 Days : Haa Valley
2 Days : Thimphu City
1 Day: Punakha Valley
1 Day: Phobjikha Valley
2 Days: Paro Valley
You're welcome to change it according to your interests in the places after reading the blog.
For the starters here’s some important info you should know before planning your trip
Bhutan currency is known as Ngultrum which has an equivalent exchange rate with the Indian Rupee. But the best part is the Indian Rupee works very well in Bhutan so one doesn't need to get into the currency exchange business.
One can travel to Bhutan by air as well as road. Both have their own charm but the road trip obviously needs more time.
Road Trip: One can catch a flight till Bagdogra and hire a cab or drive up in your own car. The immigration is done at Phuntsholing ( the border town on Bhutan side next to Jaigaon in India). A thing to note here would be that the immigration office is closed on the weekends and their national holidays so plan your trip accordingly. Other route is from Assam, the border town known as Samdrup Jongkhar.
The entry permit released on arrival is legitimate for Thimphu, Paro and Phuentsholing only. Travelers desirous of going to other towns need to obtain a route permit from the immigration office at Thimphu on any weekday.
You do not need a Visa to travel to Bhutan. A passport or a voter id card is good enough.
On reaching, one can buy the local sim cards Tashicell or B Mobile.
There are two flights that operate from India. Druk Air and Tashi Airlines from Delhi, Calcutta and Bombay,Bagdogra and Guwahati.