Miscellaneous: There are only two maps of the area that are accurate. One is an 1-50000 series maps brought out by Finnida and the government of Nepal, but while extremely accurate these are bulky. If you go the Kailash trek you will need four sheets to cover it all on the Nepal side of the border. The other is a trekking map called Kaliash & Lake Manasarovar 1:175.000 published by Map Point, available at Map Centre in Thapatali part of Kathmandu. Also the Finnida maps are sold here (see my Nepal or Kathmandu pages for exact location). It is one sheet, covering Simikot to Kailash, with best details inside Nepal. This is the only so-called trekking map that is accurate in terms of location, names and in not adding fictious settlements and wishful thinking sort of trails. Other maps do add these guesses on their maps as their research is scanty and it looks suspicious with empty spaces on maps... I have tried to find this map in Thamel, but nowhere to be found.
Luggage and bags:
Waterproof/dustproof luggage bags.
Clothing/Shoes/Weather Gear: Good boots that can handle snow/wet conditions. Bring gaiters too, to keep snow, dust and scree debris out of your shoes.
A down jacket is fine, but worthless if wet snow is the order of the day. You need to bring a rain/windproof shell jacket or anorak as well. Hat, gloves, scarf, too.
Wool underwear keeps you warm even if it gets wet.
Photo Equipment: Dust and waterproof holding bags for photo equipment.
Miscellaneous: Rarely do I recommend bringing in foods to an area of Nepal. Humla is the exception. The food available commercially here in shops and chiyaa pasals in Simkot are generally insufficient for trekkers, and the price is high. Bring trekking food, powdered soups, tea, snacks etc - whatever you need for yourself. Dinners will be ok in Humla, but for the rest you should consider BYO.
You need sturdy hiking shoes for the coarse gravel trails of Humla, heavy duty boots for higher altitudes (into Limi etc.).
Because of the altitude it gets very cold quickly when the sun vanished behind clouds or after dark. Cold weather gear is needed for the trekking season late April-September also. Long underwear, sweaters, scarves, buffs, mittens or gloves, hat... Mid winter temperatures in Humla drop to below -20C. When I was there mid October there was a sudden snowfall, and regular frost in the morning.
Toiletries and Medical Supplies: Bring medical supplies for ailmets related to cold, sore throat, headaches. I will not recommend anything for altitude sickness and AMS. Just go down, down, down and drink lots of fluids. The sun is very strong at this altitude, bring high-factor suncreams etc., lip balms and dry-skin creams. This is essential!
Photo Equipment: Take my advice: bring three times as much film as you think you will need. Beware of glare and much light. A telephoto lens is good for people photography. But note that both the maoists and the army are suspicious of such gear.
Camping/Beach/Outdoor Gear: On your own, you will need to bring all sleeping/camping gear.
Clothing/Shoes/Weather Gear: Bring a "buff" or similar face mask to keep out dust kicked up by the wind, horse hooves and boots. The dust can be particularly annoying at camp sites (esp. Kermi, Tumkot and Hilsa).