For acoustic a really easy and simple song to learn would be country songs (if you like that genre of music) ... I learned a bunch of these songs when I first started playing ...
George Strait
Adilida - Open A, E, D chords w/capo 2nd Fret
Stars on the Water - Open G, Em chords w/capo 2nd Fret
Kenny Chesney
Please Come to Boston (little harder) - Open D, G, Em, A chords - Bm w/capo 2nd Fret
Eddie Rabbitt
Driving My Life Away - Open E, A, D, C#m, E7
Drivin N Cryin
Straight to Hell - Open G, D, C
4 Non Blondes
Whats Up - Open A, Bm (I use opn chord variation), D
Tom Petty
Free Fallin' - Open D, Dsus, Asus w/capo on 3rd Fret
Bob Segar
Accompany Me - Open A, D, E
Alot of these songs are real simple and easy to learn ... the best thing to learning strumming patterns is to go to the following site I mentioned in an earlier post
http://www.justinguitar.com/
That's where I learned strumming patters in one day (it's pretty simple once you get the hang of it)
Hope this helps!