Housebreaking a puppy using a crate is a very healthy method.  Basically, dogs don't want to soil where they live.  Using a crate helps to make the dog want to wait to poop outside.  This has to be done correctly so the process is humane.  An 8 week old puppy will need to poop about 20 or 30 minutes after eating.  Placing him/her in the crate after eating and bringing them outside after this amount of time works the best.  If they don't go outside, place them in the crate for a few minutes, then put them back outdoors.  As they age, the amount of time from eating to soiling gets longer, and you just adjust to their habits.

A special treat should be given as a reward as the puppy learns the routine.

You'll find the crate will prevent the puppy from getting into mischief in the house.  You'll also find the dog using the crate even with the door open, since it is their own space.  A crate trained dog is also often welcomed in hotels and motels, and is more comfortable in a boarding kennel or overnight at the vet hospital.