Ah, mac user.
The first thing I would say would be to get a proper computer.
Seriously, when you've uploaded photos to photobucket and you hover over an uploaded image you should get a little menu pop up underneath.
When it does, got to the [IMG] code option and when it's highlighted in (green on my machine) hold down the Command button and press 'C'. This will copy the [IMG] code from photobucket into your clipboard.
Then go to whatever post you want the image in and then hold the Command button down and press 'V', this will paste the copied text into the body of the thread you want.
When it's all done, hit the submit button and you should have some photos in there.
The actual code you'll end up copying should hopefully looks something like this:
[IMG]http://i586.photobucket.com/albums/ss309/PHOTOBUCKET_username/imagename.jpg[/IMG]