In order to post comments (with or without attachments) you must register as a user on the blog.  You can find that “block” at the bottom of every post post (not any menu pages).  You should see something like this:

If you click register, you should then see something that looks like this:

From this point, everything else should be pretty self-explanatory.

If you have trouble either registering or posting a comment after registering…please “Message Me” and I’ll be happy to assist.