I haven't posted anything for a while, and am today feeling rather picturey. So here's a brief guide to some great pictures:
Astronomy Picture of the Day not only has a great daily astronomy-related picture and commentary, but is one of the oldest sites on the internet. I've been a regular viewer for years, you should be too.
The National Geographic Photo of the Day site likewise has a changing-daily photo that is beautiful, unusual, interesting, astonishing, unbelievable or all of those things.
If you need more pictures of the heavens, take a look at the Hubble Site. It has many fabulous shots of the skies, all or most of which were taken from the orbiting Hubble telescope. Look around the page and click on the "full screen" button to see the pictures in their full glory.
A few years ago, my search for some good desert photos for my aunt led me to a Phoenix-based amateur photographer named Art Brown. Art takes a lot of walks in the desert, and posts outstanding pictures along with desert/hiking commentary. If you like the desert or even if you don't, you'll enjoy these pictures. Here is Art's Desert Exploration Blog and here is a collection on another site. I've used some of Art's pictures to create some very nice greeting cards.
I started making greeting cards a while back in order to help out a friend, and the pictures we were using were of Point Lobos, a section of California coastline near Carmel. I got to be e-friends with the photographer, Chuck Bancroft, who was a park ranger at Point Lobos for 30 years or so. See pictures of Point Lobos and environs at his site, Images by Chuck Bancroft.
And here, from an earlier post, are The Top 100 Pictures of the Day from 2013 from a site called "Twisted Sifter."