make my pictures bigger

It would depend on the picture, but there is a website called photobucket - www.photobucket.com, which can help you to do different things with your photos. Perhaps you could select them in a application like publisher and change them that way.

Most photo editing programs will give you the option of resiving an image, but you will only achieve a certain size before the image starts to pixelate. The criterian is the amount of information that the picture contains because you cannot disply detail that is not in the original. Even if you increase the pixel rate per inch the image will become fuzzy when you reach the limit. An exception would be a vector graphic which should display the same irrespective of size.