I love the fact that you are targeting a specific location and product - nice sub-niche!
You need something in the header - something that defines the page. Whether that be a graphic, or text, or whatever works well there. A combination of both, probably.
I dont see a sign-up form for your mailing list
That's a must-have, of course...
I dont really care for the word "Articles" when targeting a non-marketing niche. I think it would sound better to say "VoIP Info" or something like that, because that's what those articles are. (When I click on those articles, some of them dont show up...)
On the article pages, you should move the advertisement to the right side (in my opinion) and let the words wrap around it... instead of creating an entire column for it. Also use it as a "call to action" at the end of the article. Once someone scrolls down - considering they read the article with great interest - there's nothing related to click on
Going back to the main page, the bottom half is too cramped - hard to read, simply because your eyes dont know where to settle and start. The top half looks good, though - so I would stick with that format and use those Read More buttons.
It's a great start, like I said. A few tweaks and you have a super-nice site on your hands!
