Also, how to do Hiders within Hiders. 

Go like this. 

[hider=Thing Here]

Some stuffy stuff

[hider(Put a 2 here)=Some random thing]
Random text

[/hider(Put a 2 here)] [/hider]

EDIT, so if you put the number 2, where I put the (put a 2 here) you get this. 

[hider=Random stuff]
Some text

[hider2=More Random Stuff]
Some more text]
[/hider2][/hider]