Depends, really, on the situation and what's in the contract.
If you're just designing the site, but not building it, then I think using place-holder text and images is pretty standard, but this isn't something I do, so don't take my word for it.
If you're actually building the site, then you need to work out with the client beforehand who is responsible for what. Are they going to supply the content, or do they want you to do it (or employ a content writer on their behalf)? I work mostly for small businesses, and as I always point out, they know far more about their business than I ever will, so it would be daft for me to write the content. Getting them to agree to supply the content is usually pretty easy; getting them to actually supply the content sometimes feels like getting blood from a stone. :rolleyes:
As far as photographs go, I enjoy photography, so if the client doesn't have suitable pictures, I'm happy to provide them. If it's for a commercial site, I charge extra; if it's for a not-for-profit I just throw them in free as a goodwill gesture.
Hope that helps.