When it comes to crate training puppies, one thing that I find to be an important factor is choosing the right crate. There are a few different factors that go into choosing which crate is going to be best for you and your new puppy.

First we need to remember that this is a lifetime investment, not just a tool to help potty train. This will be your puppy's home, bedroom and den as it grows into a full size dog. The first thing I need to mention, simply because it's the easiest to put into words, is the size of the crate. Since you will need it even when you're finished crate training puppies, it needs to be big enough for your dog at FULL SIZE to stand up and turn around in without having to hunch over past it's shoulders.

Crate training puppies offers extra reasons to get a specific type of crate. There are 2 main types of crates that you can look into. It comes down to weighing the positives and negatives of wire crates versus plastic crates. I'll break them down individually.

First, the wire crate.  When crate training puppies, this is probably the best.  First, when trying to introduce your puppy to the crate, it won't feel as intimidating because it's open.  Second, when the puppy is inside, it won't feel as isolated.  Wire crates are generally a little more expensive than plastic crates, but can also usually be folded up for easy storage and transportation.  

Second, the plastic crate. They aren't quite as good for crate training puppies, but in the end have more overall advantages. Most plastic crates can be disassembled to where the top will come off. This can make introduction to the crate a bit easier, but for it to be worthwhile, the top will have to go back on. Thus, it can be stressful on a new pup. However, if crate training puppies isn't the only thing you have in mind, then this could be the crate for you. Later in life, dog's will usually enjoy the privacy the plastic covering gives them. Also, all the airlines I know of will only allow plastic crates for travel. If you travel a lot, that should be an incentive.

Here's a great series on crate training puppies.