There's two ways to do it. If you have the pics on a website, you can post the link to the pics between image tags, it would look like this (without the spaces) [IMG] www.yoursite.com/kitty.jpg
[/IMG] Be sure that your site allows remote viewing. Many of the free hosts don't, like Geocities and Tripod.
The other way is to attach saved pics from your computer to your post. The pic has to be less than 400 x 400 pixels and less than 33Kb. Once you have it reduced to that size, at the bottom of the posting page (where you type your posts) click the Browse button by Attach File. Open it like you would open any file in a program. NOTE: If you preview your picture, you will have to open it again with the Browse button. Just a little glitch with the site. Also, the pic needs to be a JPEG or GIF for it to show up as a picture on the post. A BMP has to be downloaded. If the pic is too big you will get a message when you submit post/reply.
For more detailed (and I mean DETAILED!) information about this and other computer & site questions, check out Your Computer Questions...Answered in the Lounge. Feel free to ask anything on that thread, too!
Is it clear as mud now? Pics are a nemesis of many around here...(once you get the hang of it, though, it's not too bad!)