Image Tuner is a free batch image resizing, renaming, conversion and watermarking tool with an intuitive UI. If you are looking for a tool that will be able to do everything you need to do with images every day, missing Image Tuner would be a crime!
QuickResizer resizes and converts graphic files (JPG, TIF, GIF, PNG, BMP) in batches. You can launch QuickResizer from Windows Explorer's context menu by right-clicking on the file, or you can drag and drop your picture files onto QuickResizer.