Taking the multiple shots may be easy, because most modern cameras have a "bracketing mode" that will allow you to automatically take a picture repeatedly at different exposures. HDR photography works by combining several photos of the same scene, taken at different exposure settings, into one photo. There are several HDR software packages, and I've had the opportunity to review some of them.
1. Photomatix Pro is a photography software developed by HDRsoft for Mac OS X and Microsoft Windows, primarily designed to make the process of creating high dynamic range photos easier and more streamlined. By automatically blending multiple exposures of photos, it has the ability to create fully 32-bit images as well as tone mapped images.
2. Qtpfsgui - open source QT based GUI for pfstools, now including an automatic image alignment.
3. FDRTools Basic - FDRTools has bridged the gap between merging and tonemapping; the user has the ability to look at the tone mapped image then in real time edit the merging of source images.
4. Essential HDR Community Edition is a free HDR software that blows the others out of the water when it comes to tone mapping. Their goal is to better Photomatix, which has made itself the bench mark of HDR software. It has an easy interface that allows you to manipulate the image by tone mapping, histogram and color balance.
5. EasyHDR - EasyHDR is an image processing program that produces High Dynamic Range images from normal, 24-bit, true color photos taken with a typical digital camera.
6. Artizen HDR - Artizen's feature list seems to grow by the day, not only is it a HDR editing package but it also offers a wide range of basic image editing functions, including painting tools, an image browser, raw converter and more.