Simple PhotoBucket Tutorial.
This assumes you have created an account at http://www.photobucket.com and are logged in.
Click on choose files to upload your photos, this will open a dialogue box to allow you to select which files to upload, in the resize box choose 800*600 as your image size.

Once your files have been uploaded, hold your mouse over the photo you wish to insert into the forum and click on the IMG Code box, press CTRL & C this will copy the link to your photo.

In the forum, all you need to do now is to paste the link where you would like the photo to display.
Do this by clicking your mouse at the right location and press CTRL & V, this will paste your link to the photo in the forum. You won’t actually see the photo until you have submitted the form.

Remember to, if you move or delete the photos from your photobucket account the pictures will no longer display in the forum.
Good Luck
Chris.