Simplicity 5118 is a really nice peasant dress pattern.
All of those pictures are pretty much pillowcase dress with sleeves. There are a few tutorials online for how to make them. I'll see if I cna find them for you.
Also, check out sewingmamas.com I think they have it in their file/dowloads section at the top of the page.
The fern and faeirie smock pattern is the simplest one I have ever seen. Very easy to sew!
Thanks everyone for your replies. I hadn't ever seen sewingmamas.com--wow! Thanks for that link! I think I could spend all day looking at that site. And I found the pillowcase dress tutorial.
I didn't realize that Fern & Faerie had a smock pattern--I'll go check it out!