how do you make the file that holds your picture smaller to put in the post

The easiest way to post a picture without having to worry about the size is to first post it in a picture hosting site. One good one is imagestation.com. You can join it for free. Once you have your picture posted there, all you need is the URL address of the picture. To find the URL of an image, right-click on it. Then click on "properties". A box will pop up, and about halfway down it will show the URL address. You can just highlight it, right-click on it, and click "copy". Then, when you post, check "embed picture in post", at the bottom of the screen you're posting in, and paste the URL in between . The image you chose should show then when you hit "preview". If it does, hit "OK" .
If you want to post more than one picture in your post, just copy down the URLs of each picture and type each one in between , separately, and they should all show up.
example:





That would cause all three pictures to show up in your post.