I can't figure out how to override my current CSS to allow the FCK editor output to look the way it does when using the editor. :) If I change the size and font, I am assuming my skin css is overriding it and keeping all the text standardized, as it should, I guess.

Is this an easy fix? And can I apply it to certain modules and not site-wide? Any help would be appreciated. 

You can do anything you want, how you do it will depend on the module you are working and and how is gets its styles. Working with the source in the editor will also allow you to define any style you want. Can you tell use specifically what you want to accomplish and with what module?

Sir,

You just have to make sure that the style in FCK.css is the same with the style in portal.css or skins.css. When you use fckeditor, the style will be from fck.css, but when you view the page the css will be from the skins.css or portal.css. My advice, for styling typography it's better if u make it in the portal.css, because portal.css will always came last so you don't have to worry that the style will be overided by any other css file.

For more information about how the create a style in fckeditor, please check this thread
http://www.dotnetnuke.com/Default.aspx?tabid=795&forumid=-1&scope=posts&threadid=128781