Need help moving all of left hand side sideboxes

I am trying to figure out how to move the whole left hand side column of the side boxes over to make it flush with the top of my banner box. if you look here: http://greenheronbookkits.com/cart/ you can see that the categories and all below are a little to the left and I want to make that flush, if possible.

Search the stylesheet.css for

#mainWrapper

Then give it a width the same size as your header banner.

That works to change the header div with the banner and the navigation. Is it possible to change area below all of the navigation instead of having everything 100%?

Not sure what the div wrapper tag is for sideboxes / centercontent

#mainWrapper encloses everything on your page; but it is possible for individual parts to have minimum sizes (content/images/long words) that make them expand beyond where they should.

well I think I got part of it figured out. If you look at my site now, I would like to get everything centered under the header/banner now. How would I go about accomplishing that? http://greenheronbookkits.com/cart/ I have mainWrapper width set at 738px curretly but that does not seem to effect the lower portion of the page.

One problem you have is that you have emptied the right sidebar, but you haven't disabled it in admin > Configuration > Layout Settings > Column Right Status - Global.

So it is just sitting there taking up space.

well, I disabled the right side box from admin like you said but it still does not center for some reason. Any other ideas? I'm not sure why its not being effected by the mainWrapper settings.

Firebug shows that nothing has #mainWrapper as an ancestor, even though view source shows <div id="mainWrapper">, and apparently the proper </div>, although I'm not certain about that. All the spellings look ok, so I don't know why this would be not working.
Styling #contentMainWrapper {width: 742px; margin: auto;} does work, but you really need to find out why #mainWrapper is nonfunctional.

You might try adding another </div> at the end of tpl_main_page.php and seeing if that has any effect. If it does, check the div nesting in tpl_main_page.php very carefully. If it is not missing from there, I would guess that another div near the end (probably) of the page execution is missing its </div> and is stealing #mainWrapper's </div>.

I had 2 too many /div's in my header file and that was the problem. Thanks for the tips, I got it all looking the way I needed it to!