By Travelling Slacker
Delhi-Haridwar-Rishikesh-Rudraprayag-Chamoli-Joshimath-Govindghat (Motorable Road — The NH 58). Trek to Ghangaria where you stay the night. The next day trek up to the VoF and then come back. If you are going to Hemkund, it is another route from there and will take another day.
Day 0: Night train from Delhi to Haridwar. Day 1: Take early morning bus from Haridwar/Rishikesh to Govindhat. Nighthalt at hotel. Day 2: Trek to Ghangaria. It is a long trek and takes the whole day. Hotel at Ghangaria. Day 3: Trek to Valley of Flower and back to Ghangaria. Day 4: Trek to Hemkund and back to Ghangaria. Day 5: Trek down to Govindghat as early as possible, catch bus or car to Haridwar & beyond .
Budget hotels are available at 400-600 everywhere. GMVN dormitory at Ghagaria should also cost that much per head. Do note that you can't camp or stay inside Valley of Flowers. You wil have to trek from Ghangaria and return.
5 days from and back to Delhi should be enough if planned well and move continuously, but you may want to give it more time to really enjoy the experience. 7 Days should be ideal.
Kahoolawe
Hawaii
Monsoon is when the flowers bloom at the valley. The season starts in June but July and August are the best months but you must also be prepared to brave heavy rains. Carry raincoats and protect your electronic equipment with plastic bags. In September the weather gets clearer and trekking gets easier but the flowers start drying up.
There are two parts of the trek. Govindghat to Ghangaria is around 13 KMs of easy to moderate trekking. You will find food and accommodation here for the night. Next day trek to Valley of Flowers That trek used to be around 4 KMs. But newly built trek after the floods may be slightly longer. Additionally you can do Hemkund Saheb is 6 KM away on another route and will take one extra day for it.
For those who have a problem with fitness, you can find horses or mules to carry. The locals who drag them charge good money. It should cost arounf INR 1000-1500 per person on one side.
Basic restaurants serving Indian food are available everywhere along the route till Ghangaria. Langar food is also available at the Gurudwaras for free. You will not get anything inside Valley of Flowers as it is a protected forest. However, one the Hemkund route there are shops and at teh end of the trek you get free food at the Gurudwara.
Not really needed although it depends on your mentality. Even if you ask the travel agents in Joshimath they may try to get you a guide. But basically there is only one road and a sane person can’t possibly get lost. Just walk along.