Earlier in this thread someone said,
"Your best bet is to use images from sites that offer royalty free stock images."
There is a lot of misconception centered around the meaning of the phrase,
"royalty free".
"Royalty free" does NOT mean that you that you can use the image without payment to the copyright holder or their agent / stock agency / etc. It means that you pay only once and don't have to continue to pay royalties.
A good explanation is here:
http://blog.microstockgroup.com/royalty-free-photos-what-does-that-mean/
This approach to licensing is to be contrasted with "rights managed" licenses, ie,
http://en.wikipedia.org/wiki/Rights_Managed . One usually can get a clue whether or not the speaker understands this difference if they say,
"royalty free image" vs saying,
"a royalty free license".
BTW, I heartily second the recommendation of IamSam to read and follow the advice given in:
http://webnet77.com/webstuff/copyright.html . Many other similar authoritative sources exist, but this is a particularly nice summary.
In contrast, if you operate under some of the policies suggested earlier in this thread, eg,
"It's OK if it's non-commercial", "
No one will ever see it", or your own made-up, wishful thinking rules, e.g, "
I'm exempt because my post processing makes it a derivative work" or "
My posting is exempt under 'fair use' ", there's a very good chance you will indeed get away with the infringement, but you if you are un-lucky, you may not.
Finally, to help protect the owners of this forum from a claim (frivolous or not) that the forum itself is an infringer by allowing copyright protected material to be posted, I suggest that the TOS of "Photoshopgurus.com" be modified to include text to the effect that:
(a) The forum does not have the resources to check the copyright / licensing status of every image posted here, so the individual posters assume full responsibility for adherence to copyright law;
(b) Anyone who posts an image on this site gives other users the right modify that image and re-post it to this site for the purpose of demonstrating technique; and,
(c) Make the TOS easier to find. I just Googled {TOS site
hotoshopgurus.com} and couldn't find the page.
HTH,
Tom M