For the food, see Melon Slice.
Melon is a type of food in Minecraft PE. The only way to obtain their Seeds is from the Nether Reactor.(More ways to obtain them in the future.) Melons can be farmed easily, as they drop several melons each block. Also, after you harvest them, the stem will stay there and let another melon grow again. The plant will keep growing melons again and again. When a melon is destroyed, it will drop 3-7 Melon Slices. In order to gain maximum number of melons make a plus symbol and plant the melon in the middle and surround it with water, as melon plants can produce more than 1 melon per crop, and do not die by themselves. Melons spawn naturally in Jungles as of 0.9.0. Sometimes melons can be glitched if you grow the melon right by a pumpkin, where they occupy the same space, causing the melon to still be yellow but have a face.
The best way to plant Melons
A picture of melons in-game