You put a pic into a post like I did using this syntax,

[IMG]webhost url where pic is up loaded too[/IMG]

This is the code I used for the Campanian/Apulian spearman image. I stuck some spaces so you could see the code. I use ImageShack as my pic webhost.

[ IMG]http://img36.exs.cx/img36/5897/1485face0ta.jpg[/IMG ]