
FastStone Image viewer has all the features you will need, like image modification tools: Resize/resample, rotate/flip, crop, sharpen/blur, brightness/contrast, red-eye removal, emailing, resizing, cropping, drop shadow, framing, bump map, lens, morph, waves, color adjustments and digital camera support but what i like the most is the built-in batch processing (you can rename or convert multiple images in the same time).
It also has common utilities for bloggers, like image special effects: watermark, annotation, and even a screen-capture utility. Just right click an image and click Draw-board to use annotations, arrows and such:
If you only want the batch processing, FastStone provides it as a stand-alone application and you can download it also for free: FastStone Photo Resizer:
Unfortunately, FastStone Image Viewer comes only in a Windows version, but if you really want to use it on Linux, the portable version works great through Wine.