The first song I learned how to play was America'a Horse With no Name. This song requires the use of two chords (that's my kinda song!) Some versions are a bit more complicated than others, so as you progress, you can throw some extra pizzazz in there!
Here are the two notes that you will need to know:
http://guitar.freemovies.co.uk/wp-content/uploads/2012/06/A-Horse-With-No-Name-Chords.png
I have been getting all my information from a YouTube-er named Marty Schwartz, who has almost 1000 videos on YouTube of tutorials on guitar.
His YouTube account is: http://www.youtube.com/user/martyzsongs
I chose Horse With no Name initially because I love the song, but I'm really glad I did because it was really easy to learn and great to practice strumming. Here is a video on how to play and what I did was paused it on the part where the strum pattern was up on the screen and just kept running through that.
One way to make it a little more accurate (for lack of better words) is to add a little extra to it. Here is an example:
And here is the actual song! Enjoy!!