The easiest way a boxer can protect his/her knuckles is using a basic boxing handwrap. Most male adults and teens need 180" handwraps. People with smaller wrist and hands may benefit from using a shorter handwrap that's between 108"-120". In the beginning it's normal for you to experience sore knuckles, but if you constantly have these issues after several weeks of training you may need to invest in added knuckle protection.
Although knuckle guards aren't necessary they are beneficial for many, especially those who suffer from chronic knuckle pain after a training session. As a combat athlete you will be putting a lot of stress on your hands, so protecting your knuckles with the proper equipment is crucial to keeping you as pain free as possible.
There are several different types of knuckle guards, knuckle pads, gel pads, handwraps, and fastwraps on the market. I'll give my list of what I consider the best:
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.
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 Fortress T1 Fastwraps are the best brand out there in terms of hand/wrist protection.
Knuckle Pads/ Knuckle guards
Skulltec knuckle 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.