For new users and for people not familiar with the software, a little primer on how to put a picture in your post. (There are a LOT of ways. Out of all of those, this is one of them).
1: Go to
http://imgur.com/ Get a free account and stay logged in (This becomes important later in how to retrieve your picture)
2: Over toward the right it will say "Upload Images". Under that it will say "Computer" and "Web". Pick "Computer".
3: Navigate to the picture you want to upload and click "Open".
4: In the bottom righthand quarter or so of the imgur screen you'll see in green "Start Upload". Press that.
5: It will do some stuff for a while and then you'll come to a screen where you see your picture and a bunch of other stuff. This is pretty much the ONLY way you can screw up, but it's easy
6: Towards the right, you'll see six URLs called different things. The only one you care about is the one marked "Direct Link (email & IM)". There's a link below that and just to the left of that will be a little icon that looks like a piece of paper. Click that.
(Edit: I keep having people tell me they don't see that, but they never report back to me when I ask if they were logged in. I THINK you have to be logged in. Otherwise, if you don't see the direct link, just try double clicking the picture and get the URL from the address bar)
7: Congratulations! The pic URL is now in your paste buffer.
8: Now flip back to your post, hit the IMG tag (supposed to be binoculars, maybe?) and paste your pic URL between brackets.