Mala beads are a tactile reminder during meditation and chanting. In many traditions, prayer and chanting is done in certain numbers. By running the beads through your fingers as you chant you are able to keep track of how many times you have repeated the mantra or prayer. Now a days people use them to help calm their monkey minds that many people combat in meditation. Having the beads keep the mind and hands busy to help focus. They can also help with a person's breathing. Instead of chanting or using a mantra, the beads can help you to clear the mind and track the breath with an inhale for 1 bead and an exhale for 1 bead.
The most common mala bead configuration is the 108 bead mala. There are 108 mantra beads and often a head bead called the guru bead. This guru bead can be a tassel, a gem or anything that resonates with the person or it can be picked due to its intention (Example – Rose Quartz is love – the mantra can be about rose quartz).
The guru bead is important as it represent your own guru or teacher, your deity, or you Higher Self, along with your intention. You start your meditation at the first bead to the right of the guru bead and you cycle through each bead until you return to your guru bead and stop, not crossing the guru bead. There is an option to stop there or you can take hold of your guru bead and say a prayer or set an intention and then stop your meditation.
There is also a traditional way to hold your mala. The beads are held in the right hand as the left hand is seen as impure in some traditions. The beads are held and worked through the thumb and middle finger with the index finger extended (it never touches the beads). This is because the index finger is related to the ego, something that ideal is kept out of meditation. The thumb lightly pulls the bead over the middle finger.
A couple other things... Empowerment of a mala is to set your intention for a specific mala and then charge it by repeating the mantra everyday for 40 days and on the 41st day it is considered charged with your specific intention. It is said that you do not change the mantra now, this mala is specific for that mantra. If you use another mantra, you reset it to neutral... use different malas for different mantras. Also other rules, often not followed by modern westerners. The malas are not jewelry and only to be used for meditation. Yet, I found someone say that wearing it as a necklace is a great way to remember your mantra when you are not meditating. Don't let other people touch your mala. Never place your mala on the floor as it is considered dirty. A mala should be stored in a sacred place if not on your person (ex. Around the neck of a buddha statue). Cleaning your beads – singing bowl can use vibration to do cleansing is great, you can smudge with incense or sage. Don’t wear them when you are showering, bathing, swimming, doing heavy physical activity, or when you sleep. Traditionally someone is to give you your malas, not you purchase your own.
There is a lot of info out there, feel free to do your own research or whatever feels right :) Enjoy your mala.