Currently living in Kathmandu, born here and went to private school until SLC (sophomore) and then did my A levels (Junior-senior).

• Not good. The kid is most likely going to a government school, since it is unlikely there is an English medium private school out there. New school year starts from 14/15 April (Nepali New Year) and it is not uncommon for schools in remote parts not to have textbooks or even teachers for better part of first few months. It's mostly because there is very little vacation time between end of school year (right now, March) and the new one so new editions aren't printed/ready. Plus the teachers are blase about their teaching responsibilities in government school. Shitty pay and general apathy. Minimum standards are rarely enforced. Also, I wouldn't count on your kid being in third grade since kids in villages start school later and/or fail their end of year exams and have to retake it. I wouldn't count on English fluency from the kid so one thing you can do to make sure the company is putting your funds to good use is demand the kid write you letters in English. If it's too grammatically correct-don't buy it. It's probably dictated by his teacher.
  

That book is not a children's book.

Most of our English books came from Oxford India company. Learning to Communicate were the standard books through primary and secondary. You can send him those books, they have stories and exercises in them that will help with his English. Not much you can do about Nepali books, it's cheaper to buy here plus I'm sure the kid will be better in Nepali than English.

http://www.oup.co.in/series/school-education/english-language-teaching/366/new-learning-communicate-new-edition/142/level/primary

http://www.oupnltc.com/#

• No. Toothbrushes and soaps are cheaper here. Local version. I'm sure your kid can afford them. Don't bother with purification tablets-water up there is fresh from the mountain and better than the bottled stuff we buy. Poor hygiene is an issue. Toilets. Unless you plan on building one, not much you can do about it. Nutrition is also an issue since lower income family have less protein in their diets. Though, kids there get plenty of exercise. Sorry, can't help you with this one.

• Toys. Yes, kids love toys. Usually they play with the plastic-mass manufactured stuff that's the latest fad on Indian Cartoon Network (I was a fan of beyblade/my nephew loved Ben10). I doubt there's cable up there but the toys somehow make it through. You can send him toy cars/planes/helicopters (cheap Chinese knock offs will do). Ball games...probably cricket or soccer. Badminton is pretty popular as well. You could send him a baseball ball (assuming you are American and introduce him to the game-share your culture, maybe he can write to you about cricket). You can send him art supplies. Kids all ages love to color and draw. I doubt he gets to do that more often.

It looks like a fun game, I hope he enjoys it. Don't bother with anything that needs batteries or electricity. I live in Kathmandu and we have 10 hours of power-cut everyday. Plus, batteries are expensive. And don't send over something too expensive, I think it might get sold off.

If you can, send over some candy. He will love it.

I hope this helps.