If the pictures are the origional size, then yes they need to be re-sized.
Are you on a computer running Windows Vista or Windows XP? Here's a great program for XP, called Image Resizer. Go here-
http://www.microsoft.com/windowsxp/Downloads/powertoys/Xppowertoys.mspx
Look on the right side of the screen and download Image Resizer. It will give you a tool to resize images quickly & easily. Once it has finished downloading, you go to the files you want to upload to the internet, right-click on them and you will see a option to re-size image. You can then choose small, med or large and re-size the image.
I use it often and it works great.