I would love to help anyone out with graphics if I can. Maybe the other gals will post with other options too. I do have to make a personal note here.... when I pick out graphics anymore, i try to choose little(r) ones. Someone once made a good point about the bigger ones may eventually slow down the BB. With that said.... here's some tips.
for some nice graphics, you can go to - www.photobucket.com
choose the "Find Stuff" tab at the top of the page
type in what your looking for in the "Search" blank on the right hand side of the page
if anything is found, your results will pop up. If you see something you like, click on the picture itself, not the (by....?) link.
when the picture appears, scroll down the page. You will see several codes. You want the last code, which will be listed as.... IMG Code - Forums & Bulletin Boards
If you left click on it, it will automatically copy it. Then come back to the BB post you want to put it in and right click on the posting window. You should see your menu bar pop up, just click on paste. When you're done, hit post. Back on the BB you should be able to see your post. The picture should be there, if not.... hit "edit" and repeat these tips with a different picture.
Note : sometimes for me, I get an "Error" message and my Explorer window closes. But if you log back on, and go back to the BB, you will see the post actually went through ok.
Hope this helps a little.

~Chris