When you find a sig you like or want to keep, follow these steps:
1) Right click over top of it and hit Save Picture As. It should save as a .gif or .jpg file. (Make sure you pay attention where it saves on your computer.)
2) Come to your message board here. Either hit Reply or New Discussion. When the window opens to post in, click the third from last icon on the second row - it is called the "mountain icon" because it looks like a mountain in a picture frame. A new window will open, at the top of it, click My Computer. Click Browse - and choose the signature or photo you want to load. Hit Open. Then that window closes and you click Add Photo.
3) When the signature or photo opens in your post and you are ready to hit Send Message - STOP - don't hit it yet. Hit Ctrl A to highlight everything in your post - then Ctrl C to copy it. Now close the post window and open a new one - either Reply or New Discussion. Either hit the third icon on the top row (paste button) or Ctrl V to paste it in your post. Hit Send Message.
This method does not use your storage space and you can load as much as you want.