Crate-training is a great thing to do when you get a new dog. Crates provide a "home" for your dog, mimicking the dens that they desire in their instincts. If you have a puppy, it helps with potty training. The theory behind this is that puppies won't eliminate where they are sleeping, and so it forces them to "hold" it until you come back and are able to take them outside. Crates are also a great way to keep them out of trouble when you aren't home or if there are non-dog-friendly guests visiting. Just be careful not to keep your dog in the crate TOO long!
I only have experience crate-training puppies, so I'll focus on them for now. If you have anything to add about crate-training grown dogs, I'd love to hear it!
Buying a crate
You want your crate to be big enough for the dog to comfortably turn around and lie down, but no bigger (especially if you are still potty-training). If your puppy is still going to be growing, I'd recommend getting a crate with a divider. If the crate is too big, then the puppy can eliminate in one side of the crate and sleep on the other. This sounds weird, but Jera did that when the first crate we had was too big! Borrowing a smaller crate is another way to go here, and then upgrading when the puppy outgrows.
* A note about pet store puppies: Because they are usually kept in cages, they are taught to eliminate in the same place they sleep. Therefore, you may find that at first they will use their crates. This isn't natural, and if you are patient with them the first few weeks, they will learn that they don't HAVE to sleep in their own filth, and they will wait for you to come and let them out of the crate. I know this sounds disgusting, but that's what happened with Jera - we found that time was the key to stopping her from going in her crate.
Setting up your crate
We chose to put our crate in the living room, where Jera and Zoey could still feel part of the family and not "shut off". Make sure to find a place that isn't too drafty or too hot. If your dog is potty-trained, you can put a soft blanket and maybe a toy in the crate for comfort. I wouldn't recommend this if your dog isn't potty-trained though! Also, don't put any puppy pads in your dog's crate. Puppy pads have a special scent that attracts puppies, and you don't want to encourage any accidents inside the crate!
Creating positive associations
NEVER use the crate for discipline!! It might be VERY tempting, but you want to be very careful to always create positive associations with the crate. When you first get your puppy and/or the crate, start by throwing some treats inside. When the puppy goes in, praise him/her extensively. Stop praising when the puppy leaves the crate. If you continue to do this, then the puppy will learn that you like the crate. Never force your puppy into the crate. If you are having trouble getting him inside, then use treats.
This crate is your puppy's private place, so teach your children not to play inside it. Try to make it as nice and comfortable a place as you can! You don't have to add an adjustable beds, but a blanket or even an old t-shirt that smells like you can help a lot (if possible - remember, non-housebroken puppies like to use soft things). Your puppy probably won't like the crate at first. Try doing short sessions in it, to get him used to the idea of the crate and also to let him know that you will let him out again. We always gave our puppies a treat every time we put them in the crate.
Let them "cry it out"
It's heartbreaking to put your puppy in the crate and walk away, only to hear them cry after you. You just have to learn to turn a deaf ear towards it. If you come when they start crying, then they will never learn that it's okay in the crate. This killed me the first week we had Jera. My husband would leave for work about two hours before I woke up, and she would cry and howl the whole two hours. I would lay in bed, my heart twisting, but eventually she settled down and before too long she would be silent until I came to let her out.
* Note: Make sure before you ignore your puppy that she's not crying because she needs to go or because something is wrong.
Dinner time in the crate
One thing that really helped our dogs not mind their crate is to feed them their meals in it. Since beagles LOVE food, associating their crate with mealtime was a very good thing! We always did this with Jera, but when we got Zoey we started out by feeding her in the kitchen. She seemed to have some issues with her crate, and when we switched we noticed a huge difference.
Be careful not to keep your dog in the crate too long. Our dog trainer actually recommended keeping a puppy in a small dog-proofed room during the day, instead of the crate. We were never able to do that, due to not having a small room we could block off (a laundry room may be a great option, if you have one). I worked nearby, so I always came home and let the dog run around for an hour in the middle of the day. Remember: your puppy generally can "hold it" for as many hours plus one as she is months old. (So, if your dog is 3 months old, then she should be fine for 4 hours.) Don't put your dog in a position where he or she is forced to eliminate in their crate. Just keep reinforcing positive associations, and both you and your dog will do great!
For further reference:
Crate Training - HSUS