Minecraft seeds/server Xbox

Could someone please explain what a Minecraft seed is and how I can put one into my game (xbox) please?

Also, do I need a live gold to do so and suggest some good seeds/servers.

I know a very cool seed for tu14 you spawn near or in a gap which contains a stronghold and a cave that leads to diamonds just dig around the lava. The seed is herOBrine. Be sure to write the herobrine's O in capital enjoy

Ok so first you need xbox live to download minecraft in first place, seeds are just names for the random maps generated, for example if I add a seed "shadow5677" to one world and the same to another, the terrain at the start will be exactly the same. To add a seed you need create a new map and enter your seed into the second box ( I think second box) it's labeled "seeds".

You go on the internet and type in seeds for minecraft xbox360 and when you launched yah game create a new world then type in the seed where it says seed