A crate is your absolute best management tool. I cannot imagine bringing up a well-behaved puppy without a crate.
Besides being crated at night--which I feel is a must!-- here is my schedule. It may seem like too much for some people, but I'm here to tell you that this schedule will help you have the best behaved puppy (and adult dog) because you will be training your dog pro-actively to accept boundaries. When I can educate my clients in puppy classes about this schedule, they are very happy about the results.
Unfortunately many people feel that their puppy should be free with the humans in the house whenever the family is at home. This may be because they feel guilty that their puppy has to sleep in the crate at night and is in the crate while they are at work.
I also meet many people who believe that once the dog is housetrained and no longer havin accidents, that they no longer need a crate. This could be a mistake because there are so many behaviors that a puppy has not outgrown yet, like nipping, chewing our stuff, jumping on visitors, attention seeking behaviors and more. Keep the crate around for awhile. A good goal would be at least until the puppy is 9 or 10 months old (or more!)
Please don't feel guilty. Here are all of the times your young puppy could be crated:
While you are preparing and eating your food
Sometimes when you are playing with your children
When you are doing housework or something that you cannot give your full attention to your puppy
...basically anytime you cannot give your full attention so that he doesn't wander, have accidents or chew an electrical cord.
Many people tend to use their crates only when they need to and by then the puppy has already made mistakes. Housetraining accidents or chewing on the furniture are the first two that come to my mind. If you prevent accidents ALL THE TIME, your puppy will understand it so much faster. If you prevent chewing on the furniture or other inappropriate behavior ALL THE TIME, your puppy will never learn to chew. The reason why this is true is that puppies outgrow these two behaviors. If your puppy never gets a chance to chew on anything he shouldn't, by the time he is 9 or 10 months old, he won't even think about doing it. It's true, I've proven it with my dogs many times over. Unlike other people, I have never lost an item to my puppies chewing habits! Many of my clients have seen my dogs in action. They are not depressed nor did they miss out in anything in life because of my training! IN fact, they get to go pretty much anywhere BECAUSE they understand boundaries.
Another great thing about a crate trained dog is just they are comfortable in a crate whenever they have to be in one. For example: where do you think your puppy will be when he is at the vet for spay/neutering or for some kind of emergency? Imagine how much better he or she will heal when they are comfortable in the crate. If you should go away, think how much easier it will be on your puppy or dog if he can go to someone's house to stay because he is so well crate trained. Or if you have to use a boarding kennel when you travel, think how much more content your puppy will be.
Another reason to use the crate is if you have an older dog that is trying hard to adjust to the new puppy, but is noticeably agitated by it. I try to explain to my clients that the first dog deserves time to himself and time alone with you, especially at first. Too many people shower their new puppy with attention. What they don't realize is that the older dog is being put on a lower pack status than the puppy. Be sure to give your first dog lots of additional love and attention and spend some quality time with just him.
Many people expect the same good behavior from the puppy that the older dog has. Your older dog is already housebroken, should already know the rules of the house and has outgrown the chewing stage. He deserves more freedom. The young puppy is not yet educated to all the house rules and he is just too immature to expect that good behavior from him. Set the new puppy up for success instead of failure. Keep him from getting into trouble. This really works and I hope you give it some thought...