Boxing handwraps are an essential piece of equipment for all levels, whether a seasoned pro or a novice having a pair of quality hand wraps is vital. The reason you wear wraps is to prevent injury and knuckle chaffing and with the proper wrap length and wrap technique you can help prevent hand injuries.
Traditional wraps are good for most people and they are relatively low cost $6-$15. For kids 108" wraps could work, for bigger kids or ppl with really small wrist/hands 120" is suffice, but for most people the best bet is 180" wraps. I prefer 180" Mexican style wraps with a little bit of stretch to really get a nice contoured fit for my hands. If you can pick up a wash bag for your wraps I highly recommend doing so, it keeps your wraps fresh and they don't get all tangled in the wash. The Everlast 1910 are amongst the best traditional wraps in my opinion, I even prefer these over winning's wraps, which are too narrow and delicate for my liking.
Sometimes Traditional wraps aren't enough especially for those who suffer from severe hand/wrist issues, so for those people I would recommend something more sophisticated. The bandax elite and elite+ are great convenient alternatives to tradiontal wraps. Bandax offers a foam padding options and a Gel and foam option (elite+) that offers great knuckle protection and added wrist support.
For those who just need knuckle protection:
for those looking solely to prevent knuckle pain and don't require wrist support I would recommend Skulltec Gel pads or Fortress Nano wraps. There are other gel pads and knuckle pads on the market; such as, winning knuckle guards, or any other generic boxing brand, but those aren't as good as the ones below.
Skulltec Gel pads are amongst some of the most popular gel pads today. They take the brunt of even the heaviest of hitters and disperse the energy so you don't feel it in your knuckles. They are a great band for buck coming in at $24.99 and come in two models. The green version is 1/4" thick and the purple model is 1/8" thick for those needing less padding.
Here's a link to a video on how to wrap your hands with Skulltec gel pads below: