Get the high-quality Pro Series Billiard Glove. Full fingered and fully reversible for either hand.
To find out your size, put your hand palm down on a piece of paper and draw a line on either side at the widest part. Don't include your thumb. Measure the distance between the two lines.
Small = 3 1/8" or less
Medium = 3 1/8" to 3 3/4 "
Large or X-Large = 3 3/4" and up