Brian, you may want to give credit where it's due, noting the fact that the photos you're providing a link to areon Lost Liners.Com
On the matter of any other photos, make sure you have the permission of whoever owns the copyright to the photos to post them directly to ET. The first point is a courtesy, but the copyright issue is a legal necessity which we take very seriously here.
Brian, as Michael said in his above post, any photos that you post directly to the ET site (as opposed to linking as you did above) need to be either in the public domain or you must have permission from the copyright owner. Anything that was published prior to 1923 is in the public domain (but scans out of a book published since are a gray area to avoid).
When linking, it is customary to indicate that you are linking to a specific site. (i.e. Take a look at these photos on LostLiners.com: ).
There is a photograph of the Lusitania showing smoke coming out of stacks #2,3, and 4 but none out of the first (most forward) stack. Was this a "dummy" stack as on the Titanic or just a case in which all the boilers were not fired up at the time the photograph was taken ?