If you have microsoft office picture manager, you can do a very quick and easy resizing of photos.
Open your photo in Picture Manager
Click "edit pictures"
Underneath "change picture size" you will see two options:
"resize" (allowing you to resize the photo either with a custom size, a pre-determined size, or a percentage of the original size)
"compress pictures" (which reduces the size of the photo and the file size, in 3 different increments)