I believe Linux Magazine is US based.
But to be honest with you, the magazines are not going to be your best source of linux news and knowledge. That, of course, will the net and here. The DVD's and CD's on the mags are a good way to get a distro, but many times they are already out of date by the time you buy them. As an example, by the time Fedorca Core 5 hit the cover of Linux Format in the UK, there had already been three kernel updates. The magazines are a nice diversion but my advice would be to get the software online.