Well, it so happens that I spent many hours, just about a month ago, researching juicers.
There are two kinds, mostly. One is centrifugal, the other is masticating.
The centrifugal ones are the ones you commonly see at places like Macy's or Bed Bath & Beyond. They have a wide mouth, and they spin at thousands and thousands of RPMs. They're often less than a hundred dollars, sometimes less than fifty.
The masticating juicers spin very slowly by comparison (less than 100 RPMs). They are more expensive (a couple of hundred dollars at least).
Pros and cons:
Centrifugal juicers allow you to throw huge pieces of fruit and vegetables in. Masticating juicers require you to cut the fruit or vegetable into smaller pieces, as the chutes are typically much smaller than centrifugal juicer chutes.
Centrifugal juicers subject the foods to high heat due to the enormous amount of RPMs that the juice is spun at. The heat destroys some vital nutrients and the juices that are produced should be consumed right away. Masticating juicers produce a more nutritious juice, because the foods aren't just spun to death, they're slowly crushed and extracted. The juices can last for up to 72 hours if they're kept in an airtight container in the fridge, and they will still be good (72 hours is not ideal - they should be consumed quicker than that, but studies have shown that masticated juices retain more nutrients and for a longer period of time). Masticating juicers expose the foods to less oxidation, and we know that oxidation isn't good for foods (it's what turns apple slices brown).
Centrifugal juicers don't handle leafy greens and wheat grass well. They're best for fruits. Masticating juicers easily handle kale, spinach, wheat grass, and other greens.
Centrifugal juicers pretty much do one thing. Masticating juicers can crush nuts for nut milk or make nut butters. The one we purchased, the Omega 8000S, also has attachments for making bread sticks and noodles.
Centrifugal juicers, because of their RPMs, can wear out a little more quickly. Masticating juicers last longer.
Centrifugal juicers can take up less counter space because they're vertical. Fruit drops in, juice pours out. Most masticating juicers are horizontal in design. The fruit or vegetable pieces are dropped down a small chute, where an auger spins them and crushes them and after traveling through the auger, the juice pours out of the spigot.
Centrifugal juicers produce a wetter pulp. Masticating juicers produce an almost dry pulp. The pulp is great for composting, feeding chickens or birds, and mixing into dog food (assuming that whatever was juiced is suitable for dogs, like carrots, peas, and other pet-safe foods). Some people make homemade dog biscuits using the pulp from dog-safe foods. The pulp also makes a great homemade vegetable stock. Just collect the pulp from juiced vegetables in a freezer bag or container. When you have enough, dump it all into a big pot of water and simmer away for a few hours.
We got the Omega 8000S on amazon.com and it was just a little less than $300 on sale. It comes with a 15 year warranty, and it's quiet. Easy to clean and put together. We chose that over the Breville because of the longer warranty, and the additional features.
Store the juice in a glass pitcher in the fridge, not in a plastic one. If plastic pitchers must be used, they need to be BPA free. If the juice is going to be consumed over a couple of days, just tear a piece of plastic wrap and lay it on top of the juice before putting the cover on the pitcher. A large mason jar is a good choice for storage.
I also own a Vitamix. A Vitamix is great for so many things, but technically it doesn't "juice". It produces a liquified smooth mixture, but it contains the pulp of the foods that are blended. I use mine for smoothies, soups, homemade peanut butter, sauces and so many other foods.
Even if you don't rely on juices every day, there's nothing quite like fresh orange juice on a weekend morning!
Hope that helps!