In order to adjust the styling of a p element within the blog post, add a style with the selector .blog_body p, so that it only applies to the p elements under the div styles with the blog_body class.

Hope that helps,

 I find this discussion thread a bit confusing.  Here are some of my issues:

1. I run a web site in which unfortunately the blog entry paragraphs in the blog module are different than paragraphs in an HTML module (I was trying to get them to be the same).  Looks like the skin.css Normal section does have control over paragraphs of the HTML, but not the same control over paragraphs in the blog entry.  

2. Modifying blog_body in the module.css file does change the blog paragraphs, but the end result is still different than the paragraphs in an HTML module, even if css values are the same.  Adding blog_body p does the same thing as modifying blog_body.  The problem with blog_body and blog_body p is that now paragraphs look different under Google Chrome and IE (The only way to get the paragraphs to be the same is to actually use inline css for each <p>.  Changing the skin.css, on the other hand, produces consistent Chrome and IE results for the paragraphs in the HTML module and, if I remember correctly, for the blog module, with the only issue that then the blog and HTML modules differ).

My issues are mostly with font size.  I am not looking for a solution, as I am happy to add the font-size css inline, even though that makes my HTML heavier.  I am just mentioning these as they may prove useful for future development consideration.