If the paper you are using is not acid free, I would recommend either buying the Archival Mist spray to treat it, OR make sure that it does not come in direct contact with your photos.
If you "lift" pictures off the Web, it would be a good idea to jot a light note on the back of your pages to ensure that you never submit the page for publication or for a contest -- and of course you should never in any way sell anything that has someone else's work on it.