1- Yes- in kindergarden hw only came home on fridays but sight words where to be practiced every night. 1st grade we had spelling every night and Tues was to read in our reader. Since first grade, on top of hw they also have to read for 20 mins a night and keep a log of how many pages they read.
2-I help with the hw
3-Kids usually have a snack right when we get home and then we start the hw. I tried waiting until later but they are too tired and whinny by then and it is just awful (this is just what happens at our home but probably not all). I do let them wait until later before bed to do their 20 mins of reading.
4- Usually the dining room table where it is quiet and they can spread their stuff out if needed. It also helps me see what each of my two kids are working on. I usually check folders while they start there work and I am there if they need help with anything. Some nights they do, some they don't but they know that I am there for help if they need it.
5- Find what works for you and your kids. We tried several different options in kindergarten until we found the schedule that worked best for us. Each family is different, some kids need the down time after school even if it is 30 minutes to watch a favorite tv show and have a snack and then hit the books, for us it was better to just get started right after snack. No distractions and then they could do whatever they wanted. I usually give them until after dinner to start their chores (trash, dishwasher, feeding pets) so they do get a good 1-2 hr break and can relax, they need it just as much as we do!