Are you trying to upload pictures form your computer or are you trying to make them appear by linking them form another site ? 

If linking them from another site on the web that site may not allow linking of those images to another site ?

How large are the pics you are trying to make appear here ?

If uploading fomr your computer they need to be around the 100kb range. If linking them form elsewhere on the web there should not be an issue with their size.

You can download Pixresizer for free here.

http://bluefive.pair.com/pixresizer.htm

You can also download the MS powertoy for resizing images here if you happen to be running XP. It makes an option on you right click menu to resize pictures on your computer without altering the originals. It's really the simplest to use.

http://www.microsoft.com/windowsxp/downloads/powertoys/xppowertoys.mspx