Image posting:
As Rosy says, there's heaps of sites that allow you to upload images. I use ImageShack
http://www.imageshack.us/.
It's reasonably painless. Go to the site, click on browse, find the picture you want from your computer, click on OK, then click Host It! on the web page. If it's a massive image, you can select the resizing option, which will crop it down to a nice, forum-sized image. But that isn't a huge problem, as you'll see soon enough...it just takes longer for the image to be uploaded.
It then, after a while (depending on how fast your internet connection is) comes up with a lovely page with lots of stuff on it. I generally ignore most of it.
Now, there's two ways you can display the image, either as a thumbnail (as I've done with the above and below pics) or as a direct image. If you want to thumbnail it, just click once in the "thumbnail for forums" box and press Control + C, or right-click and select Copy from the menu. Generally this is best for larger images (told you you'd see soon enough
).
If you're only posting a small image (like the one I've posted at the bottom of this post), you can skip that and just highlight and copy the text in the "direct link to image box".
Now come back to PRE, write out your well thought out post or whatever and then, when you're ready to attach the picture...it'll depend on how you're planning to display the picture.
If you're thumbnailing it up (cough), simply paste (Control + V or right-click - Paste) the text directly into your post, no need to muck around.
If you're using the direct link, you need to click on "Insert Image", just below the italics button. Two little tags will be inserted into your post, [ img] and [ /img] (without the spaces). You'll notice that your cursor has been moved so it's between these two tags. Now, all you need to do is press Control + V (or right-click - Paste, but make sure you're pasting it between the tags).
Now its simply a matter of pressing Preview to make sure it worked...and then press Post and Bob (and all his brothers except maybe one, if that one is your father...oh shhh) is your Uncle!!!
Exhibit A:
btw...can I get that added to the Smiley list, by any chance?