So say I have 4 images: <img><img><img><img>
and I don't want any spacing between them so the images line up.
How can I do this?

use this way:
<div id="no-space">

css as follows:
#no-space {width:100%;}
#no-space image { padding:0; margin:0; float:left;}

or you may add this css on top of your style sheet
* {padding:0; margin:0;}

please let me know if any points

Actually, I found out that because I was doing
instead of <img></img><img</img>
So thanks.