minecraft classic and minecraft beta singeplayer, all on minecraft.net
no there is not in classic if your talking about old, beta version i think so but idk where.
Go to www.yoyogames.com and you should find good tutorials. If you are using an older version you go to www.wiki.yoyogames.com
In classic Minecraft (versions prior to Beta 1.3), diamonds were not available. Diamonds were introduced in Beta 1.3, which was released in August 2011. Prior to that update, players did not have access to diamonds, and the game's resources were more limited. If you are playing a version of Minecraft that is Beta 1.3 or later, you can find diamonds deep underground and mine them with an iron or diamond pickaxe.
Type in 'minecraft server hosting' on google, and you'll find a ton of hosts for your server with tutorials.
There is only one version of Minecraft currently sold by Mojang. It costs $24.99 and give you access to the current version of Minecraft and future updates. You can find Minecraft Alpha codes on eBay for $10. These (should) give you the current version of Minecraft.
There are many tutorials on youtube that you can watch to find the answer to your question and will be much more specific to your needs.
The full version of the Minecraft game can be purchased from Minecraft's own website, and is available for PC and Mac, as well as Android and iOS systems.
You cannot download Minecraft Alpha. You can only play it on the Minecraft site. You can find it by going to Minecraft.net, and under the "Buy Now" button it has buttons to play Minecraft classic (Alpha) either in multi-player, or single-player.
Not in the current version, at least not often.
The XBox 360 version can't be modded.
They are found in plains, in version 1.6 and above.