when you say resize what exactly are you referring to? are you trying to change the resolution for viewing on the web or are you actually cropping the pictures smaller? You have several things to look at when resizing for the internet. First the resolution, which will affect the speed at which the image loads as well as the clarity. Next is the images pixel dimensions. What program are you using to resize the images?
for example I use a resolution setting of 72 for the internet and the pixel dimensions of around 600 px on the long side. Some programs such as photoshop give you a quality adjustment as well. if you lower this to much your images will become a little blurry.
images that you intend to have prints made from you should leave the resolution at 300 dpi or greater and the quality setting at 100. Prints can be made from the lower resolution files, but anything much larger than a 4x6 will start to show pixelation (grain in film).
hope this helps!