Lots of people believe in crate training a new puppy. It is always a good idea to keep your puppy in a safe place while they are not attended, whether that is in a crate or in a designated room/area. They can get into a lot of trouble if left free to roam the house (not to mention potty training:)
A large crate is ideal for any size puppy, especially young puppies. They will not be able to hold their bowel movements for long periods of time. It would be best to give them a big crate with plenty of room. You can add blankets and stuffed animals to make them more comfortable, as well as having an area with puppy pads for potty.
Puppies also cannot go without food and water for more than a couple of hours when they are under 16wks. It is a good idea to leave puppy food and water in the crate with them as well. Sometimes leaving a radio on will soothe them. And always their favorite toys to keep them busy.
As they age, you can judge their behavior and when it is safe to leave them out unattended while you are not home. Start with short periods of times away from the home and work your way up.