if your using photoshop you can just resize it. and if the file is too large you can just click file then save for the web.. it compresses the file and makes it smaller.
Adobe ImageReady is probably the app for getting pics on the web. Editing pics in Photoshop can make them bigger, especially with CS2 which I have now. I always run them thru ImageReady before I upload anywhere.
download this program...all you have to do is go to the IMAGE tab and choose size and you can size the photo however you like..than you just save and the program automatically makes the file size (not size of the photo) much smaller. remember to go "save as" and make sure its set to JPG.