How does one get to post attachments?

 

click on the "Go Advanced" button below the text box

you'll see a few icons on the new page that are immediately above the text box. let your mouse hover and they'll tell you what the are for

I'm pretty sure you can only post links, pics though.

what do you mean by attachments?

 

Do you mean post an image in your post in the forums ?

Just look about 4 threads down from this one to see the instructions.