Overview:

Annapurna is the 10th highest mountain in the world and was the first 8000m peak to be climbed. It was first summited in 1950 by Maurice Herzog and Louis Lachenal. It was not until 1970 that Annapurna was summited again. In the autumn of 1999 there were 120 expedition to Annapurna. 106 climbers reached the summit. 54 climbers never came back.
However, I am assuming you are more interested in trekking the Annapurna region , so most of this information will pertain to trekkers considering this trip.

When To Climb:
The usual trekking season in Nepal is from October to May. The rest of the year is the monson season and is not desirable for either trekking or expeditions. Besides the cold and rain, leeches are a problem during the monsoons. If you are going to be trekking to Annapurna, October and November are the best months.

Mountain Conditions:
Trekking possibilities are quite varied, but most will start at Pokhara. The circuit trek to the Annapurna Sanctuary will take at least 10 days, but allow 14 to have time to enjoy it and to allow for unforseen events. The route up the narrow Modi Khola river valley is quite wet and slippery and quite steep in a few places. It can be a bit dangerous. The trail up to the Annapurna basecamp is a more serious undertaking.

Itinerary A:

Day 01: Arrive Kathmandu and transfer hotel
Day 02-03: Kathmandu official work & preparation for expedition
Day 04: Drive to Pokhara
Day 05: Drive Suikhet and trek to Pathana
Day 06: Pathana ? Ghandrung
Day 07: Ghandrung ? Tadapani
Day 08: Tadapani ? Dobatto
Day 09: Dobatto ? Chistibung
Day 10: Chistibung ? Khubra
Day 11: Khurba ? Base camp of Annapurna South
Day 12-24 Climbing Period Annapurna South.
Day 25: BC ? Shownta
Day 26: Shownta ? Ghorepani
Day 27: Ghorepani ? Birethati
Day 28: Birethati- Nayapul drive Pokhra & Kathmandu
Day 29: Kathmandu
Day 30: Final Departures

Itinerary B:

Day 01: Arrive Kathmandu and transfer hotel
Day 02-03: Kathmandu official work & preparation for expedition
Day 04: Drive to Pokhara
Day 05: Drive Suikhet and trek to Pathana
Day 06: Pathana ? Nayapul
Day 07: Nayapul - Deurali
Day 08: Deurali ? Himalayan Hotel
Day 09: Himalayan Hotel ? Machapucherre Base camp
Day 10: Machapuchere Base ? Annapurna South Base camp
Day 11-23 Climbing Period Annapurna South.
Day 24: Annapurna South ? Himalayan Hotel
Day 25: Himalayan Hotel - Deuralli
Day 26: Deurali ? Ghandrung village
Day 27: Ghandrung - Birethati- Nayapul drive to Pokhara
Day 28: Drive to Kathmandu
Day 29: Kathmandu.
Day 30: Final Departures

Cost includes:

1. Permit Fee (Royalty) of Annapurna South
2. 5 nights accomodation with bed & breakfast at 3 star Hotel
3. Kathmandu - Pokhara - Kathmandu transfer by coach
4. Full board trekking with lodge & Food for BC Expedition period
5. Porter to BC & while back Pokhara
6. Equipment: trekking equipment for BC, 1 tent for 2 persons, dining tent, toilet tent, table and chares, Mattresses
7. All kitchen equipment for BC
8. Liaison office allowances ,staff's equipment allowances, flight ticket, insurance for staffs
9. Annapurna Conservatio Fee.
10. Local Transfer airport-hotel-airport
11. Staff: Base camp Guide, Cook, Kitchen helper
12. All necessary taxes.
13. Agency service charge

Cost does not include:

1. Personal expenses
2. Lunch and dinner in Kathmandu.
3. High altitude (climbing) food, fuel, Gas above BC & personal climbing gear each climber
4. Personal accident insurance and emergency evacuation, Helicopter rescue
5. International Airport Departure Tax
6. Nepal custom duty for import of expedition goods arriving into Nepal, cargo.
7. Bar bills & beverage.
8. Extra expenses for personal
9. Climbing Sherpa