I know Jimmy and other battle reporters use a program called battle chronicler found here
http://battlechronicler.com. It's a windows only program. It takes some getting used to and it has it's quirks. I think over on Ulthuan.net someone had a guide to creating battle reports using the program, embedding and making your own effects - like the nice explosions Jimmy puts on them.
Embedding is pretty straightforward, you embed the way you would embed pictures to the site using a photo hosting service like photobucket. I believe battle chronicler spits out half turn by half turn *.jpegs that you can then embed. Like I said, I've only briefly played with it.
Here's the forum topic -
http://www.ulthuan.net/forum/viewtopic.php?f=51&t=37809