Cycling gloves are basically designed to protect your hands in the event of a crash. Unlike work or ski gloves, they have the tips of the fingers cut off, so they’re not too hot. (Although winter gloves have full fingers, more like ski gloves) They also offer padding on the palm area for comfort on long rides. Don’t worry to much about gloves – just find a pair in the size that fits in a color that matches your scheme (get black to be safe in this area) and you’re set!
The better gloves have better cushioning on the palms, which can make a big difference in long rides. More expensive ones have gel inside the padding, which works quite well, as it adapts to the shape of your hand on the handlebars better.
Another reason for gloves is that they almost always have a small, terrycloth area on the top side. This will typically be advertised as something designed to wipe the sweat of your brow away. Although it kind of works for that purpose, the real purpose is to wipe your nose! See the section on gross stuff for more details on this often undisclosed side of cycling!
Also, when you choose a pair of gloves, I highly recommend that you get washable ones. I own multiple sets – I just throw the dirty, snot-covered ones in the laundry basket after a ride. Many people, unfortunately, only own one pair and use them over and over, not unlike a dirty handkerchief, which I find gross!
Finally, beware of racing gloves. They frequently have no padding and no snot wiping surface. They’re also very hard to get on and off, since they’re designed to be very tight fitting and ultra-aerodynamic. If you’re a pro this may be fine, but for us amateurs it’s simply unacceptable!