my family have been using dish washer for around 20 years in Taiwan already, i can tell u some of my experience.
when my family first install a dish washer, most people in Taiwan don't even know there was such a product. most people's first reaction is... it won't clean as good as hand wash. i can tell u from my experience that the cleanness of dish washer is unmatched by human.
ok, speaking of dish washer, there are 2 type. the first one has heater build-in. so u only need to feed the machine with cold water and it will heat up and wash. the second type of course is like washing machine (for clothes) where u connect with cold and hot water.
before put in the dish washer, just rinse off and put it in. make sure u remove all rice from the plate.
there is a new type of dish washer has a disposal build-in. it is very convenient that u don't need to pre-wash.
detergent is the most important part. ALWAYS use detergent specially for dish washer. those kind of detergent has very little bubbles unlike regular one.
if you are going to use infant products, i will suggest to use hot water to rinse it before give to baby. usually, there will be slightly detergent left which is not harmful for adult.
generally speaking, German and American brand clean better. Japanese brand are more quiet. if you can afford a BOSCH, u should go with it. the BOSCH in my Taiwan's house has been working for over 10 years and still working like new. (My parents use it everyday) I think it can laste at least 15-20 years.... i don't think a Japaneses brand would last that long.