I use photobucket. Create an account and upload your pics to the site and then copy and paste the link.... or you can attach pics by uploading them directly to the post. Just make sure they are within the size requirements.
Someone showed me this Shrinkomatic software. Its free and easy to use. You can resize, change quality by decreasing jpg quality and do drag and drop of entire directories of pictures to a certain size ratio. Very powerful and quick. You can specify an output directory and it suffixes the pictures so the originals are intact.