Text justification

I've taken over a website that was put together with Dreamweaver, and I'm no Dreamweaver expert.  There is a main template that lays out the header and sidebars, and most of the individual pages are based on this template.

I've obviously done something wrong to the template, I guess.  In the past, when I wanted to create a new page, I just pulled up an old page, saved it under a new name, and then made the changes I needed to make to it.  The basic page had a title and a main graphic followed by text.  The title was centered, and the graphic was centered, and the text was left justified.  I've obviously done something to screw this up, even though when I look at the code it looks like it should be right.  When I put my cursor into the text region and select the CSS window, and select the "left justified" icon, everything on the page gets left justified, including the title and graphic which I still want centered.

I think I've done something to the template because now all pages on the site (hundreds of them) are all fully center justified, and I can't figure out how to get the text left justified while leaving what needs to be centered, centered.

I'll be glad to share files with someone if the will help.

Rocketman