A weight trainer should use weightlifting gloves because:
your palms will callous up and become quite rough with out them
they will protect the skin of your hands from tearing. Especially when doing an exercise that causes the bar or handle to rotate in your hand (e.g. bicep curl)
they will protect your rings from scratching and breaking (I broke my favorite ring bench pressing without gloves)
Click here for a big range of lifting gloves from Bigfitness
Weight Lifting Gloves 
