It is great that you decided to play the guitar. At first it is fairly intimidating because other people and guitar players in concerts are just so much better. However, it is important to keep learning the basic techniques.
Once you have acquired your guitar the best place to start teaching yourself guitar is learning the chords. You could get these from a book but there are many websites online that show you how to play just about any guitar chord you would ever need to know. Practice the fingerings on these and memorize how to do as many as possible. Using G, E minor, C, and D you should be able to play many of the songs that you know and love. Practice moving from chord to chord even though it may seem difficult in the beginning.
The next step to learn is strumming. Strumming is really about rhythm. For some songs it is difficult to strum them properly because they are complicated. Listen carefully to the rhythm of the song to get the strumming. At first the best you might be able to do is to just hit the right chord at the right time. As you get better, your strumming will get better.
Learn guitar tablature or tab. Some musical academics do not like guitar tab, but it is really useful for beginners because it is easy and helps you play riffs that it would otherwise take you quite awhile to learn on your own. Guitar tab shows the six strings of the guitar and will have numbers on each string. The numbers mean that you play the fret on that certain string. Just play the tab from left to right and you will be playing the song.
If you want to get a teacher to teach your specific techniques, do not do so until you have learned these basics. This will save you money on at least your first four weeks of lessons.