If you are writing pages of website content, if you use facts/statistics or photos from a different website, is it ok to use them in your content as long as you correctly cite where you got them from?
I think it's probably best to email the website owner first and ask them - especially where photos are concerned. I don't think there's any issue quoting stats though as long as you paraphrase and link.
I think if it's a picture created by a website owner, like some infographics or drawing, it's better to ask for a permission to use it. The same thing with the photos. Google this article: "Use of photographs from social media in our output". In this article BBC folks apologized for using photos of Twitter users without permission and attribution. So, do not make the same mistakes.
General facts that you can get anywhere most likely don't need citation. But information you can't get anywhere except for a few sources, would be wise that you credit them. It's always better to err on the safe side.
Yes obviously, if there is some person involved in the photo you copy, you should contact the site owner or the person and ask if you can copy those photos. I have come across many of my competitors sites, where they just copy the photos of mine in a seminar or with my staff and display it as their company, by some changes in photoshop. Later I have to send them official emails to take down the photos, its really irritating, so better ask first.