I have an ASP web page which has a style sheet attached. It is a news page which is added from a separate admin section. The news adding section does have a rich text editor to change text or format it.. My problem is this.

The CSS stylesheet is set up to show the body text as below.

Code:
      body,p,td{font-family:Verdana, Arial, Helvetica, sans-serif;font-size:10px;color: Black}
this is fine on most pages, however in the page which has the body of the article i want it to show a font size 12, with wider line spacing. If i alter the CSS code above, it alters the body on other pages which i don't want changed. In short i'm happy with a size 10 font i only want one section of the web changed, but i'm finding it very hard to do that. I use dreamweaver, but don't know how to use it properly.

I tried altering the code of section i want changed but it still keeps showing the one on the stylesheet. It does however show the line spacing. How do i get it to alter the size to size 12? It completely ignores the below, except the line- height.

Code:
 <span style="font-family: Verdana, Arial, Helvetica, sans-serif; font-size: 12px; line-height: 15px;"><%= CONTENT %></span>
Is there a hierarchy that stylesheets follow?
What i want is a size 12 font, with wider line spacing than the default for this section. One and a half size line spacing would be OK.
I'm totally html illiterate, so any help appreciated. Thanks in advance.