I was looking on the Minecraft wiki and I saw that it doesn't tell you were to find the specific biomes. It tells you what they are and what is in them but not where to find them. On average would they be? Like near the ocean, next to a forest biome, etc.
The biomes in Minecraft are generated via a random seed. If you want to know exactly where everything is, you'd have to first know the given seed. For example, there is a birch forest at coordinates 0, 0 using the seed
JAMESOFDAPEACH, but on any other seed there might not be a birch forest there.
In order to use a seed, click on "More World Options" when creating a new world and copy/paste the seed into the box. You can try this out:
JAMESOFDAPEACH in there with cheats enabled and then do /tp @p 0 150 0, you'll be in a birch forest. But if you generate another world with a slightly different seed, there won't be (most likely).
Use a site like this one to view some user-submitted seeds and descriptions.
There are some basic rules to the "random" generation though: Next to an ocean there are beaches, and biomes with cold climates won't occur next to a warm climate as of 1.7. (jungles and deserts shouldn't be found next to taiga and ice plains). The hell biome is only accessible in the Nether, and I believe the sky biome was intended for the Sky Dimension but never implemented - instead the Sky biome is for the End.