for geocities.. it'll be up for a day or two at most, then when they spot that it's a remote linking they'll stop it.
host it up on any of the sites mentioned in this thread... then when you are posting, just above the white space is the tool bar which can make ur letters bold, italics, underline.. the same symbols used in Winword. There is an icon that is yellow background, and a sorta mountain design on it. Click on it, and there'll be the place u paste the address of your picture. To find the address, just right click on your photo (at the place U uploaded) and it'll be listed.
Goodluck!