Should I use iFrames?

I’m having a problem with a site I am building and right now it looks like using iframes are the solution.

Having never used them before I was just wondering if there are any reasons I might want to avoid them? Just curious, I don’t want to launch the site and find out three weeks from now about some negative issue iframes cause.

Anything I should look out for? I know a lot of mobile devices don’t support iframes but that’s about it.

Thanks!

If you are just starting to build a site, why would you want to use iframes? ... or are you talking about just "frames"?
iframes are for bring in content from some other web page into the page being displayed. While there are occations where that is helpful, it's should not be used in any major way if you are just starting to design a site.
http://www.w3schools.com/tags/tag_iframe.asp
Overall layout should be done using elements that are positioned using CSS.
Review the "box model" here:
http://www.w3schools.com/css/css_boxmodel.asp
General HTML here:
http://www.w3schools.com/html/default.asp
info on CSS here:
http://www.w3schools.com/css/default.asp
The above links will give you plenty of basic info on how to lay out a modern Website.
Best wishes,
Eye for Video