Here are some helpful tips...
1.to post a video, there are to ways
-click the video icon and post the url
-copy the code and post it in the topic/reply
2.to post a pic, click the image icon then put the url of the pic
-the other one is to copy the code and put it in your topic/reply
3.to make a link, click the chain-looking icon and put the url
Note: when making a post/reply on a topic, don't type in the subject... just type your post/reply on the topic, [remember, don't mind the subject on making replies to topics]