I have written in the past about the benefits of watching your puppy with a close eye, and also how important it is to have your puppy follow you rather than the other way around. There are several other benefits to tethering, especially with a young new puppy.
When house training, its impossible to learn your dogs potty cues without watching them. If you have a smaller dog, its even more difficult. When you tether the lead to yourself (such as your buckle) you can constantly see if your dog starts sniffing the ground to look for a potty space. When they do, scoop them up and take them out.
The second benefit is training your dog to watch you and follow you. Most dogs learn to pull on leash because they are never used to walking. By having your dog tethered to you, you can effectively teach your dog to pay attention to you and where you are going.
Thirdly, when you are ready to wean your dog from the tether but not necessarily from watching them all the time (say around 5 months of age) if the dog is used to following you, you don’t need to worry because he is used to going with you.
Many times I hear from owners that they don’t like this idea, its too hard, they will step on the dog, etc. Its a lot like riding a bike, wobbly at first but once you learn it you can act as an effective team. Remember tethering is only for the first few weeks, and to be used as needed. If you need to gain more attention, or if you need to housetrain, tethering your dog is a great idea.