If you are lucky, the breeder has begun to crate train your puppy while it is still in the whelping box.  If possible get a piece of bedding or toy from the breeder, one which has the smell of the litter on it.  This will help the puppy feel at home.  When you first bring the puppy home from the breeder, have the crate ready and comfortable for you new puppy.  Treat your puppies crate as if it were a bed that you would sleep in.  Make it an inviting place for your puppy to call his own.  

Crate training should be done positively with no negative associations.  It is important that you do not force your puppy into his crate or use the crate as punishment.  It will teach him to feel bad when he is there and you want him to enjoy going there. When you first show him his crate give him a treat inside and just let your puppy explore his new area  Leave the crate door open and let him come and go as he wishes.  He will grow to love his little den and will begin to go there for his naps and quiet time.  Once he is used to his crate and willingly comes and goes you can move to the next step.

When you finally decide to close the crate door, turn off the lights and talk softly to your puppy.  Let him lick your fingers to assure him that all is ok, then walk away to a place where you can hear, but he can't see you.  If your puppy whines it is probably because he knows he is in a new situation.  Just like with a child you don't want to teach them that you will come when they whine so just let him cry for a few minutes   If he hasn't quieted down after 15 minutes or so take him out and give him some love, letting him know that it's all OK, then try again.  You should find that once he will quite down in just a few minutes. 

After the puppy is grown a little and is used to being in his crate at night while you sleep, you will begin to see something wonderful happen.  When your puppy is tired and he wants some time alone, he will go to his crate and curl up and go to sleep all by himself.  I leave the doors to my crates open and my dogs will go in and out to nap during the day.

At eight weeks you cannot expect your puppy to go more than four hours with out pottying.  So, as soon as your puppy whines after waking up take him out, praise him softly and gently for a job well done, then when he is through bring him back in without stopping for a play session and out him back into his crate.  Two or three nights of this and your puppy will be used to the routine.  As he grows and is able to hold it longer you will notice that he is sleeping longer.  If you happen to sleep through your puppies whining and he potties in his crate, don't scold him.  It is your responsibility to get the puppy out before he soils his den.  You want to make sure to change the bedding and try not to let it happen again as you don't want your puppy to get used to sleeping in his own mess (or you will constantly have a smelly soiled kennel).  When they are young puppies they usually have to potty every three to four hours.

At some point you may have to go to work or leave your puppy.  Make sure before you leave that the puppy has exercised and pottied.  It is helpful if he has played a bit and is tired.  If you puppy has a collar take it off and remove any unsafe toys that he may choke on or get hurt with.  He may wine a little, but just walk out and he will quiet down.  If you have to be gone for more than four hours it would be best to come home or have someone let your puppy out to potty and exercise as it is hard to retrain a puppy that is used to soiling his crate.  If you have to be away from home more than 5 to 6 hours at a time (of course adult dogs can hold it for 6 to 8 hours depending on the dog) I don't recommend kenneling them.  Puppies just cannot hold it for that long and you really don't want them to relieve themselves in their kennel.  I recommend a fenced area, inside or out, where their kennel is available.  If you are leaving them fenced inside Wee Pads are available at most pet stores and you can easily train them to go there rather than the floor.  This will allow your puppy to leave his kennel to stretch and to potty rather than being uncomfortable in a soiled bed. 

I hope that this has been of help to you and made you feel as positive as it really is.  Crate training is really a safe and natural method for your new puppy.  Also, I have found that the old adage " you can't teach an old dog new tricks" is completely inaccurate.  I have very successfully used these same methods with dogs of 1 year and older.  Good luck and remember to be patient while he learns his new home and routines.