One way to upload images is to go to one of the image hosting sites such as
http://imageshack.us
Here are instructions using imageshack:
1. When you get to the imagechack site, hit the Browse button, then select an image from your computer and double-click on it.
2. Click the "host it" button. Be patient, large images could take a while to upload.
3. The next page will provide several code snippets you can use. It is best to use the second one, entitled "thumbnail for forums (1)" Just click on the code to select it, then right-click and choose "copy". You can then return to the forum and paste it in.