There is a new procedure for posting pictures on the forum that is a little bit less cumbersome than it used to be. It still requires you to host your photos somewhere else (like photobucket), but then you can put one of their tags directly into your post.
1) Go get an account at a photo hosting site (photobucket.com)
2) Once you've uploaded your pictures there, each picture will have a series of options beside it like this:
3) You're looking for the one that says "IMG code". The bottom one in this case. Copy that whole line and put it into your post.
4) When you save your post, the image will display.
If your photo hoster doesn't supply that IMG code link, it is super easy to build off of the image direct link. All you have to do is add the IMG tags before and after the direct link like this (don't miss the fact that the closing tag looks different than the opening one - you need that "/"):
Here's a hint about getting the direct image link. Unless they're using trickery, most places on the internet that you see an image, you can right click on it and choose "copy image location" and that will give you the direct image link. The direct link to images on Facebook can be gotten that way for example.