Make them small using a resize program so the are under 100k. Then post you message click the attachment button A little window pops upload and select then close the window. You got a picture in your post
the easiest way to load the pics is to create a free account at www.photobucket.com and load the pics there. you don't have to worry about the size on that site, they can be as large as you have on your computer. then when you want to insert them into a post on az, click on the little icon that look like this:
and cut and past the direct link of the picture you want from photobucket into the dialog box and click ok. very important, then take your cursor at the end of the line that appears in your post (after the last ]) and hit return. you can preview it to make sure it works.