You can find it in caves and on the side of cliffs. It is the most common ore.
minecraft classic and minecraft beta singeplayer, all on minecraft.net
The beta version of Minecraft was released on December 20, 2010.* * Minecraft-beta came after Minecraft-alpha, but before Minecraft 1.0. You can play Minecraft-beta with the new launcher.
You can find it on the Minecraft forums.
No, the only gems in Minecraft as of Beta 1.7.2 are Diamonds and Lapis Lazuli.
You can find coal veins almost anywhere. Look at the side of stone cliff faces.
You can generally find coal underground located within the rock layers, but you can also find it sometimes on the surface.
Underground
You can find coal by mining but you can get charcoal by burning wood.
There are not many Beta servers up at the moment, but the ones that are can be found with Google. engamma.dyndns.org
no you need minecraft beta to play beta servers
The regular download as of Minecraft 1.8 is the Beta Minecraft. The last Minecraft update I believe will be the "Final" product and official game and no longer be a game in Beta.
When the full Minecraft game is released you will have it if you buy the beta.