I know the maximum height can only be 325 pixels. However, if my signature (which is exactly 325 pixels tall) is to the right of my text, is it still breaking that rule?

NO matter where your signature or forumtext is, combined they may not extend 325px height. This also includes text, which is +10px every line, so keep that in mind when you put links or credits in your signature.

How can I get my signature like yours so that my text just goes to the next line when it reaches where my signature is?

You update your ForumText (not the signature) Under Site preferences - Forum Options using this code: [img align=right]your image url[/img]forumText[br clear=all]

: ) Alright, thank you!