We often have discussions about megapixels. I found the paragraph copied below useful. If you would like to read the post I took it from, it's here
http://www.photographybay.com/2008/02/19/10-tips-for-breaking-into-commercial-magazine-photography/ 8. Use realistic equipment.
You don’t need a $5,000 warhorse to build an image archive you might use to sell 10 photos a year. But you do need a bare minimum. Most magazines publish in 270 dpi (300 dpi for artistic or glossy publications). At 270 dpi, a ten megapixel camera can make an acceptable two page (or “double-truck”) image in horizontal orientation. A six megapixel camera can handle one full page vertically. Those are the baselines. If you can afford ten megapixels, get them. If you can’t, don’t sweat it; they’ll be affordable any day now. Do not waste editors’ time with images made on a two megapixel point and shoot camera (publication of images like that effectively ceased three years ago). Don’t waste their time with ancient slides, unless you were especially good at slide photography.
