First learn your basic Open Chords. Practice switching chords (very slow) from like E to G to C to D and so forth... Part two, learn your major and minor scale pattern. There's lots of useful information on the internet to learn the scales... Also begin slow and work on accuracy...
Next: your best friend will be a metrodome, it's a must in order to develop accuracy and speed, but the key is, is to start slow until you can play either that scale, strumming, or chord changes with almost your eyes close.
Once you feel you have mastered a certain excercise, increase the metrodome by 5 bpm's and so forth...
Final: ask ask ask as many questions, usually everyone has a different approach to excercises for guitar and all are useful. (for reference by a chord and scale book)