is there a simple way to post attach a picture other than figuring out URL etc.

Only gold members can send pic via a conversation.
If you are trying to link to a picture that is already online somewhere, then the URL is required so your post knows where to find it.
This would be a simple copy and paste of the URL into your post.

If you are trying to upload a pic to a post, then the "browse" for your picture box should come up.
If it doesn't, then you may have a popup blocker stopping it.

If I am misunderstanding your question all the above may be pointless. :D