Pictures For DVD is a free little program that helps you to prepare pictures for writing onto DVD. You drop one of your picture folder onto this application and it generates a simpler, smaller copy of the folder called "for-dvd":

If you had pictures in lots of subfolders, this utility flattens them all into just a single folder with all the pictures in order. This can help you visualize and sort them all together. It's also needed for making a Kodak PictureCD, where you're not allowed subfolders.

If you had pictures with long filenames, this utility renames them all into 8.3 format suitable for PictureCD.

If you had excessively large pictures (e.g. 10 megapixel photos from your digital camera) this utility shrinks them to a size appropriate for DVD so as to make them easier to work with.

If you had subfolders, this utility creates a "title page" for each of those subfolders. This way you can watch a slideshow of your photos and still know what the directory-names were.

To use it: drag and drop a folder with pictures in it onto the application's window.

The source code shows how to recursively scan a directory, how to respond to WM_DROP, how to use GDI+ to load and resize a jpeg.