I'm sorry for the large images but I think the problem started when they were imported from the computer to tinypic.com. I should have set the size to "message board" then. I did select message board when I copied them to the text which made them huge. Look for more practice attempts in the "garbage" section; plus it gives me another excuse to get out!
I don't know much about tinypic. I post photos from Flickr.com. Their "share" feature gives me a choice of size for the shared photo. I can select small, medium, large, etc., with pixel size right there to select. Something around 500 wide is a good size for a forum.
Some more recent posts on another topic have photos so small they can't be seen, like thumbnail size. Again, we have to click to see the photo and then back click to read the forum about the photo. That's not a good answer either.
When you post a link from tinypic or elsewhere you might try adding this text in the script: width="500" height="281" That creates a proper size on the page here.
And Flickr is following the all too common web tech crap by messing up their web site to make it much less functional. Maybe the new "style" works better on cell phones. But it sucks for desk computers. And their front page "share" feature only will share to facebook, pinter, etc. I had to click on the photo to go to the older page where it would provide a scrips.
Bob