How do I put pictures in my thread post?

In your Forum Control Panel make sure the setting labelled 'Use rich edit box when composing messages?' is set to TinyMCE. This will give you a toolbar like you'd see in MS Word for your training log and forum posting.

To insert pictures use the button in the toolbar that looks like this: 

The picture has to be on the web already, you can't upload directly from your computer to the training log. If you want to use a picture that's in your BT album, make sure that you get the url by right-clicking on the picture, not by copying what's in your browser's address bar.