I switched from Windows to Mac this summer. I just copied my image files to a portable drive and then imported into iPhoto (which comes with the Mac). I think iPhoto is pretty decent for folks who just want to take pictures, have the ability to share pictures with others, and have the ability to touch them up a bit. Editing capabilities are limited but you can easily do things like crop, straighten, fix red eye, and adjust brightness, contrast, color balance, etc. File management capabilities work fine for most non-pro photographers who don't shoot huge quantities of files. If you shoot in RAW you'll certainly want to consider alternatives. I've been doing most of picture management stuff in iPhote and then using Light Zone when I want to do more extensive image editing. Aperture 2 is basically a professional level work flow tool. I downloaded the demo and have played with it quite a bit. I like it but to really make use of it you need to learn the keyboard shortcuts. Something like Aperture 2 or Light Room would probably be indespensible for high volume photographers. I decided Aperture 2 was over kill for my needs right now. Photoshop is basically the king of image creation and editing; very powerful but overkill for most folks, expensive, and it has a steep learning curve. But if you're into cutting and pasting head shots of your friends into the middle of a flower it's a great tool. You might also take a look at PhotoShop Elements 6 which offers much of the image editing power of PhotoShop but it's much less expensive. I believe you can download a demo version as well. I think I may try it and compare it to Light Zone. You can also pretty easily link an external image editor into iPhoto. For example, I can cal Light Zone from within iPhoto, edit the image, and then save back to iPhoto.
