If you have more specific needs and would have programmer resources available, the Django programming framework can offer a great starting point for building a magazine that is adapted to your business needs. Many online editions of news papers are build leveraging this software.
I believe that WordPress is your best option, and you can even check out the WordPress Stack Exchange site for answers to questions you have once you set up your site. As far as a theme to use, I suggest looking at StudioPress themes, their service is outstanding! WordPress is the most popular CMS being used, and because of this, I think offers the most options and access to assistance.
The big difference between something like Wordpress and Drupal is contributing users. Wordpress is more suitable for the sole contributor and Drupal is ideal for multiple contributors. So if you plan to have multiple writers then you really need to go with something like Drupal.
Drupal 7 was recently released and it's quite the upgrade. They worked really hard on usability.
A great way to try Drupal 7 is with Drupal Gardens. It's a hosted solution by Acquia (founded by Mr Drupal himself). You can have a site up and running within minutes for free. Their pricing is very reasonable if you grow out of the Free plan or you can export your site and host it somewhere else at any time.
I think you should ignore religious arguments about PHP, Ruby, Python etc. Your starting a magazine not a software company. So you need to focus on getting the right tool to solve your needs. Programming language really doesn't matter.
Frameworks will give you a little more flexibility to do anything you want but you then also have to do everything. That flexibility would allow you to do bad things just as much as good. You'll spend valuable time and money developing very common components that have been done hundreds of times before. Using a tool you'll get the benefit of thousands of hours of other developers optimization and as long as it's open source your really not giving up any flexibility. Underneath any tool is a framework and programming language that you can tweak until your heart is content.
drupal / joomla are better suited for magazines - finer grained control of pages, sections, content blocks, modules. Wordpress is easier, and magazine type templates abound, but once you get started you'll hit article placement limitations pretty quickly. Start considering a gallery, directory, classified section - and then you start to push wordpress well beyond its initial capabilities.
Don't get me wrong - wordpress is great. But use the right tool for the right job - joomla, drupal, silverstripe all are much more than a blogging system.
Wordpress is great for this application. Get a magazine oriented theme and you've got a solid out of the box magazine site.
If you will have user contributed content however, you may want too look at Joomla or Drupal.