1.  Open the image in MS Paint or PC Image Editor to see the size of the picture.
Note that if the picture is too large, it will extend off the page to the right... so you might need to reduce the pixel size of the picture in order to fit onto the page. 

Reduce the dimensions of the picture to something lower than 600 pixels wide - depending on the image.

Save the smaller picture to your hard drive.

Once you are ready to upload one or more pictures to your website, log in to the website with an account that has access to edit pages.

Go to the page you want to edit:

Create a new Annoucement article or a new Text-Html block, depending on how you want your item to display. 

Browse the Server directory to find a suitable place to upload your picture to. 
Keep it organized.  Don't just upload everything into one directory, which would make it hard to find things later.

You are now looking at the Directory structure on the website.  Choose a directory to upload your picture to, or create a new sub-directory.

Here I am creating a new Folder on the server called Website_Tutorials.
Notice there are NO SPACES in Folder names or file names.

Once you have chosen your directory, it is time to upload the new picture.
Click on the Browse button in top right corner... which will browse for the picture on your hard drive, then click the Upload button... and the picture will be uploaded onto the server in that directory.
If you have a problem uploading a .gif, .jpg or .pdf picture, email the Webmaster to check your Uploading Permissions.

After your picture is uploaded, you will see it.
Click on it once to select it...

which will next show you the Image Properties window.... where you can choose a Border, align left, align rright... and other placement options.  If the image is a thumbnail that will link to a larger image on a different page, click on the Link tab and choose the full-size image that this thumbnail will link to.

Click OK and your picture is inserted onto the page.
Ta-Da