Photos are available in multiple resolutions.  The approximate sizes are "thumbnail" 169x126, 640x480, 800x600, 1024x768, & "original".  Unless they have already been cropped, originals are either 3872 x 2592 or 3008 x 2000.  You can copy any of these sizes to your computer.  Use the size to determine the maximum size of a print.

Clicking on an album link will bring up a thumbnail list of the photos.  Use PgUp/PgDn, Up/Down Arrows, the scroll bar, or your mouse wheel to scroll the window up or down.  Click on a thumbnail and a window will pop up with the photo.  Next Page