How do I get a normal URL link to appear in the iframe?

like just a simple like this. www.yada.yada.com (http://www.yada.yada.com)

not quite sure what you mean do you mean how to link a page to the iframe using a hyperlink?

Yes! That's what I meant. Haha.

right you will need to look at your I-frame code, for an example look at this

<IFRAME name="inlineframe" src="yoururl.html" width=200 height=200 marginwidth=0 marginheight=0 frameborder=0 scrolling=auto></IFRAME>

so your link becomes:
<a href="inline.html" target="inlineframe">Your link name here</a>

You may have a different name so adjust it to your coding :)

to follow luvharts example, to get a different site to appear into your iframe...

<a href="http://www.yadda.com" target="inlineframe">Your link name here</a>

but... many other sites will have a small javascript in them that will not allow them to be seen inside someone elses frames or iframes. it will actually take the link and fill up the full window or create a new window. if this is the case, there isn't any way to counter-act such a script.