Use an uploading/hosting site, like imageshack.us, imgur.com, photobucket.com, etc. There's a bunch.
Then, find the appropriate place to post them on the forum. If they're a rip, make sure to put it in the submissions forum. If it's a custom sprite you made that you want critiqued, or help to get it on the tSR website, put it in the Spriting and Pixel art forum.
To post the image, get the direct link of the image from your hosted site, and do this [img]*[/img] Paste the website where the * is.
I'm sure there's a topic that goes more into detail but I don't want to look, so that's the basics.
Probably in the rules section. If you don't understand, look there.
Then, find the appropriate place to post them on the forum. If they're a rip, make sure to put it in the submissions forum. If it's a custom sprite you made that you want critiqued, or help to get it on the tSR website, put it in the Spriting and Pixel art forum.
To post the image, get the direct link of the image from your hosted site, and do this [img]*[/img] Paste the website where the * is.
I'm sure there's a topic that goes more into detail but I don't want to look, so that's the basics.
Probably in the rules section. If you don't understand, look there.