1) use photobucket after you upload pictures, each picture will have links you can copy, you have the option of choosing: a) direct link b) thumbnail picture c) img tagged link (if you copy and paste this link into your post, it will show the pic immediately)
[use 800x600 btw as default in photobucket]
ex. img tag looks like this: [img ]http://www.photobucket.com/yourname/picture.jpg[/img] -> without the space
2) use microsoft picture manager, photo editor, or any pic editor to crop your picture first. after cropping, resize the longest side to the maximum pixels allowed by the forum.
3) any link you post here will automatically be clickable