1. Open up an Image you'd like to resize in Adobe Photoshop
2. Adjust the image size according to your preferences. Image > Adjustments > Image Size. Write down the new dimensions.
3. Open up Image Processor. File > Scripts > Image Processor
4. Select the source folder of images to resize
5. Select the destination folder where the new images will be saved
6. Under File Type, check "Resize to Fit" and enter your desired dimensions
7. Uncheck "Run Action" unless you have an Action you'd like to implement
8. Click "Run"
9. Check new images and make sure they've processed correctly