Luggage and bags:
One Backpack...and one day bag.....bum bag is optional....
you can also bring in a duffel bag...which is what the porters find more comfortable to carry, as they combine two duffels and tie them into one pack to carry.
Clothing/Shoes/Weather Gear: Shoes - trekking shoes with ankle protection - well worn in...or they will bite badly
Tevas - always good to have them or trainers for the evenings...and for the days when you are not trekking.
Toiletries and Medical Supplies: Toiletries - minimum...sun protection 40+ SPF (water proof)....biodegradable soap...(save nature) and lip balm...of course the toothpaste and toothbrush...some people also like bringing moisturisers...
Ladies remember, you will be too tired at the end of the day to really be beautifying yourselves...so the rest of it is useless.
Photo Equipment: As you want of course...digital is common now...you can charge the batteries at places..so you should be fine...
If you have a regular camera, you can get rolls along the way...but carry enough as they are more expensive on trekking routes
Camping/Beach/Outdoor Gear: Camping is not recommended in normal trekking routes...as the villagers make more money when you stay in their lodges, and there are enough of them. Supporting them is more important. Other gear you will need will be
Sleeping bags and liners - specially fleece liners are excellent...most sleeping bags should be -5 above
Lighters - so that you can burn the toilet paper if you use some along the way
Swiss knife - always useful...
water bottle and water purification tablets.
Miscellaneous: some bags for bringing back your garbage
games when you are bored - though you should not be
notebook to write your journals
Nepal is facing a severe power shortage, and as a result, power is not available for about 20 hours every day.
It depends on your luck whether your hotel has some back up power supply arrangement. It would be better if you carry a pocket torch AT ALL TIMES.. you never know if you will need to go to the washroom at night.
The shopkeepers often do not have any arrangement for backup power supply. However, it is often difficult to see their merchandise clearly even during daytime. So a pocket torch would be something you wont regret having carried with you.
Miscellaneous: If you wish to visit any/all of the Durbar squares, prepare to walk through narrow, dusty alleys where you share the path with motorcycles and cars that belch a lot of fumes. To be sure you don't choke to death before you reach the square, bring and use a face mask that snugly covers both nose and mouth. Wear sunglasses too, to protect your eyes from sun, dust and the stares of souvenir hawkers/touts.
Luggage and bags:
You can buy in Kathmandu
Clothing/Shoes/Weather Gear: Good variety found in Kathmandu at good prices
Toiletries and Medical Supplies: Can find what you need
Miscellaneous: Do bring a torch light with. As it gets dark, power failures are very common and the streets can be very dark. It is actually important to have a light source with you.
Luggage and bags:
Ensure that your bag does not exceed 15 kgs or they hit you with big overweight charges on local flights.
If you have an iceaxe pack it well or it will ruine your luggage
Clothing/Shoes/Weather Gear: Lot of hiking clothing is availabe in Kathmandu and no need to buy from the US/Europe if you don't really will no reuse it.
Its cheap and its functional for 20+ day trek after that the zips break etc,etc - what do you expect.
Toiletries and Medical Supplies: Medical supplies are a must even though you can buy even prescription stuff over the counter. Its better to take stuff from here.
Photo Equipment: Cut down on weight, try to keep to a maximum of 2 lenses if you are carrying an SLR. Avoid digital cameras as battries die quickly in the cold and re-charging is not that easy other than few tea houses
Camping/Beach/Outdoor Gear: I did an escorted tour so didn't have to care about this.
The roads in Kathmandu are bad, and it rains quite frequently. Even in summer when it gets too hot, it rains afterwards, making the roads terrible to walk on. So make sure you pack some all weather shoes/sandals.
You can also buy the same there if you wish. You get many cheap ones there.
Camping/Beach/Outdoor Gear: You get good trekking equipment there and it is cheaper than in the western countries.
Miscellaneous: Carry a torch since there are frequent power cuts and not all places have power back up.