There are really two different ways to post pictures.
One is to put the pictures up on a web posting site and provide a lint to it here.
The second more common one is to upload them from your computer.
This may sound complicated but it really isn't.
You want your pictures to be 800 X 600
The way I down size my pictures is I e-mail them to myself. When you select a picture to be e-mailed your software will ask you if you want to send them full size or downsize. One option will be to downsize to 800X600.
Select the 800X600 and e-mail them to your self.
When they arrive in your in box save them to a folder on your computer.
Now you are ready to post a topic with pictures, enter your text into the box, directly below the box is "Attachments and other options" when you click on this you will be able to browse your folders and click on the pictures you want to attach. You have to do one picture at a time.
If this does not make sense send me the pictures and I will post and attache them to a topic you would like the associated with.