I can't post a picture to save my life. Don't know what I'm doing wrong.
1. The picture can't just be on your computer - it has to be posted somewhere on the internet. Plenty of services available to post your pictures for free.
2. Once you locate the picture on the internet, right click on it and go to "properties". An address for the pic will come up. Highlight it and click "copy".
3. Back in your post, type:
< IMG SRC="" > . . . except leave out the spaces before and after the carets (those sideways arrow thingies.) (If I didn't put those spaces in there, you wouldn't be able to see the html command.) Then click in between the quote marks and paste in the address of the picture.
That should work!
AnAmericanMother has it right. I use photobucket.com and find it a pretty good service. You upload your pictures to it from your computer, and it will show you the pictures along with the HTML to display them.