Posting images directly to the site from your computer is the recommended method as unlike Photobucket or online sites the images will remain as accounts change etc.
To so is a very straight forward process.
1.) At the bottom of your post click on + Attachments and other options
2.) This will show a number of options. Click on the Choose File button
3.) This will open a dialog box asking you for the location of the image to upload from your local computer. You can upload up to 6 images per post - with all of them being no more than 7 mb in total. (To upload totals larger than than hit the preview button, and then attach additional files.)
The site has no disk space limit so this is not an issue. Again all are encouraged to upload photos but, it is a matter of personal taste.