"generally" puppies lose their baby teeth around 4-5 months old. You might see a tooth on the floor, or notice bleeding gums, this is all normal. Continue feeding as you normally would. Maybe provide a chew or a frozen washcloth, just like babies (humans) it can be uncomfortable for your puppy. Mostly you want to make sure that the baby teeth come out and that they are not still in when the adult teeth come in as this can cause some misalignment in the mouth. Some puppies also may get the diareah (can't remember how to spell that). Extra cuddles never hurt!
Kathy