Make sidebar text smaller than post text in WP

I'm not sure if this goes in the blogging category or programming category...or maybe both. Well, I was wondering if anyone could tell me how to make my post and sidebar text different sizes in my wordpress.org blog. I'm not a coder, but I'm guessing I have to add or edit a code in my theme's CSS. Would anyone be willing and able to answer this question? Thanks

 

Dashboard -> Presentation -> Edit CSS -> Add to existing CSS
You need to edit font-size for entry and sidebar.

 

Thanks for the reply Diana. Here's the part for the body:

body{padding:0;margin:0;font-family:arial;color:#000000;font-size:12px;line-height:16px;background:#fff url(bg.jpg) repeat-x bottom;}
ul,li,ol{list-style-type:none;padding:0;margin:0;}
a{text-decoration:none;color:#339900;}
a:hover{color:#aaa;}

I don't think my css file has a seperate font-size line for entry and sidebar.

 

I don't know how your css looks, but try to search something like this:

#entry {
some text in here;
font-size: 30px;
}

the line in red is what you want to add, and you can replace 30 with what size of font you want.

Either for sidebar:

#sidebar {
some text in here;
font-size: 15px;
}

 

Thanks for your help Diana. I have rep'd you