Steve it's not too hard.
Even a dummy like me can get it right once in a while.
First you have to have a basic understanding of the file system on your computer. Most modern computers make it pretty easy with the latest versions of Windows. Can't help ya if you're usinga a Mac.
So if you know what "folder" your pictures are kept in, you're good to go.
Simply start your post and enter the text you want included.
Before hitting "submit reply" go to the bottom of the page and click on "manage attachments."
This will bring up a box that reads,"Upload a file from your computer" with a button that says, "Browse" next to it.
Click on "browse" and find the file you wish to upload. Choose that file then click "upload."
After a few seconds you'll see that it has been uploaded succesfully and then you can close that window via the "close window" button on the top right.
Just hit submit reply after that and you're good to go.
There's other ways to insert pictures into posts and to use picture hosting websites, but I think this might be the easiest way to start off for now.
Attached is a pic of my ugly mug and my beautiful wife.