I use www.blogger.com. I just looked at the settings for my blogs, plus checked the help - and you can set up a blog with multiple members with the purpose of allowing all members to post. You can also allow comments by anyone. (I've turned the comments feature off in my blog.) On the photos front, you can either refer to photos that you have stored elsewhere (which is what I do since I already have a photo gallery set up on www.smugmug.com) or you can use Picasa (also owned by Google / blogger.com) to post your photos.
Examples? My blog is at denisegoldberg.blogspot.com. There are a few pictures included, but if you want to see an example of a blog with more pictures you can look at my 2004 Hawaii blog. Oh, and the format of the blog is up to you. There are quite a few formats to choose from, or you can create your own. I like simple, and the format I'm using is one of the standard formats (with a few color changes).
I've been very happy with using Smugmug for my photos, although it is a service that costs $29.95 a year. Yes, I know there are free services out there, but I wanted to be able to set up a gallery where the whole world couldn't print my photos. While Smugmug supports printing by both the gallery owner and anyone who is browsing, I have the "everyone else print" feature turned off in my galleries. Actually that was only one of the reasons that I chose Smugmug - but I've been very happy with it. For an example of how it looks, you can see my photo galleries at denise.smugmug.com.
--- Denise