do you have photoshop? Use the Image Processor and you can batch resize several images at once. I've used it for up to 200 images once and it took only 15min (would have been hours if I had done them individually myself).
Make sure all images are flattened first, then go into File > Scripts > Image Processor
Then use these settings, you can choose smaller or larger for the resize, but I wouldn't go much bigger than 500x500 px for posting. The 8 is just in reference to image quality. You can experiment with it a little bit and see what size and quality level works best for you with the smallest file size.
Put all the images you want to use on the web into one folder, say on your desktop. Select that as your source folder. Then you need to create a folder to poop out your jpegs to. Make sure you name the file you're poop'n 'em out to clear as to what they are ie "images4web" or "wakeworld_posts" so that when you come across a folder fulll of jpegs you know what they are and they are easier to find this way. Make sure also to click "convert to sRGB for web use and you defenitly want to save as jpeg. Tiffs and raw images are far too large to use on the web plus you don't want high res copies of your images floating arround on the web.
Hope that helps. Good luck and can't wait to see some pics!