nyati13, just google what you want and when you find the picture right click it and copy the properties of it, click Img button on the board then hit paste and it will link it in your post.
That works fine till that web server realizes you are using them as a hosting service.
And some photos or images are copyrighted, with the website having a bit of code written in that alerts them to the fact that an image has been ripped--some folks have gotten nastygrams with a letterhead that has a long list of names at the top--Jones,Smith,White,Black, Gray, Grey, and Blue---- Attorneys at Law.
"It's in the public domain" is no longer a steadfast defense.
And don't do it with anything you really need to remain posted. If it changes it's name even by one letter or number on the original website, or is deleted there, the hated redX will show up here instead of an image.