several ways. Before you up load them you can trim the borders and re-size the photos in a photo editing programe. I use Microsoft Photo editor which is ancient but works very well and is really easy to use. you just click on the 'edit' button select resize image and if you want it lets say half size you click on 50% and it will re-size the image to half the original size. For larger images i use Presto image folio.
if you have microsoft office go into microsoft office tools and open the Microsoft picture editor. this is the programe that superceeds MS photo editor. You can also use that to resize the photos.
The other option is when you upload them to where ever you are hosting the photos ( Village Photos, Photo Bucket, Windows live spaces, etc) you can select if you want to up load the photo and keep it the original size or upload it as a smaller image.
