I use Word now but I would like to find a better software for laying out a magazine.
In this magazine, I would like to create columns (2 or 3 depending on the page), insert image on 1, 2 or 3 columns (like in a newspaper), independent frames on 1, 2 or 3 columns with text inside, a header and a footer different for the left or right page, etc.
In professional design circles, "layout" and "Word" don't generally appear in the same sentence unless accompanied by various expletives unsuitable for a public forum. So it's not hard to get better than that.
What's best for you very much depends on your needs. You're asking professionals for an opinion, and naturally enough we tend to suggest the tools we use. Ask a construction carpenter about power tools and he's likely to recommend Milwaukee or DeWalt, professional tools beyond the needs of a homeowner who only needs to put up a shelf every so often. We're the same way.
A small-circulation freebie such as a church or community group newsletter doesn't necessarily have the budget for a fully professional layout application such as Adobe InDesign (the king of layout programs) as mentioned by Lauren and Scott. If this applies to you, an open source possibility is Scribus -- not the easiest thing to learn, but probably quite adequate. There are budget "homeowner-grade" products such as Print Shop and MS Publisher (the very names send shivers down my spine, but I'm not in your situation). Learning resources are a bit problematic with Print Shop, although the Broderbund website says video tutorials are "coming soon." Microsoft does have tutorials on Publisher, and the latest version, while by no means a professional layout program, has fixed some of the more egregious flaws of its predecessors.
For the highest quality and greatest flexibility, especially if you already use Photoshop for your images, nothing compares with InDesign. The big plus is that on the Adobe TV website, lynda.com and many other places you will find endless and excellent video tutorials to get you from the beginning essentials to a very sophisticated level in quite a short time. It is an industrial-strength application with capabilities far in excess of your immediate needs, but skills learned with InDesign are also quite salable. If you think you might one day want to do this kind of thing professionally, this is where you should start.
And another point that's worth mentioning: it's always much easier to get a professional result using professional tools. They aren't harder to learn, they're just more expensive because they have a great deal more capability than the homeowner versions.
You can always download the trial version of a program, do some tutorials, and know fairly quickly if it will work for you.