Manali can be reached directly from Delhi either by air or road. HRTC and HPTDC operates buses. flights are by Deccan & Jagson Air. I went to Manali from Shimla.
Going to Manali from Shimla is tough. There are buses by Himachal Roadways. Traveling even by the deluxe bus can be tough.The deluxe bus leaves Shimla t 8.30 in the evening and reaches Manali at 5.30 in the morning. It is advised to travel on empty stomach before boarding these buses. The twists and turns on the road can make you stomach throw up all that you have had at the dinner. In case you have strong stomach still the noise made by co-passengers while they throw up can make you nauseous. HPTDC operates a luxury coach which leaves Shimla in the morning and reaches Manali in the evening.
Manali is definitely better than Shimla. Even tough Manali is at a higher altitude the area is more or less even. The Mall Road at Manali is a poor copy of the Mall Road at Shimla. Manali is full of hotels. HPTDC operates several budget hotels and it canbe booked in advance through internet. Hotel Rohtang Manalasu is around 10 mins walk from the centre. Like Shimla hotels in Manali are expensive. Manalasu coasts around 600-1000 Rs. The rooms are very ordinary and old. But they are clean, food is good and staff very cooperative. However it is not suggested to go to HPTDC hotels without reservation.
Rohtang pass is the prime attraction of Manali. Kullu is around 1.5 hrs from Manali and can be visited if you are interested in buying shawls.Other places include manikaran, Nehrukund etc. There are places around Manali for people who are inclined to adventure travel. The Beas river passes right though the city. The mountain twhich are very close to Manali have snow covered tops.
Manali can also reached from Delhi. HPTDC operates luxury Volvo buses to-from Delhi. HPTDC operates two Vovlo buses to Delhi from Manali. One is old and another is new. The old buses have their shock absorbers broken and the bus is poorly maintained. The journey from Manali to Delhi takes14 hrs and is much better compared to the road from Shimla to Manali.