We have all been in the position of being overwhelmed by all of the available resources when picking up the guitar. There are so many resources in fact that it is hard to decide where to turn to start learning, just prolonging the jam sessions. Just remember that all people learn differently so make sure you give all of the following options a chance because some may work for you, some may not. You just have to find the one that works the best for you.
Personally, I improve my playing the most when simply playing. Not set songs, no rules for beats per minute, no required scale, just me and any thought that comes to my mind. I love to just throw on a backing track and play and if anything I come up with happens to work out and sound good, I write it down as quick as I can before I forget it. Eventually you will have pages and pages filled with ingenious riffs that you can always go back to and play for some fun. I always love seeing what I came up with weeks moths and years ago to see how much I have progressed. I believe that is why this is my personal favorite way to learn, the progress is displayed right in front of you in some illegible scribbles that you were so excited to some up with at the time.
If you are not yet on the level of being able to hear a backing track, think of an appropriate scale, and solo along to that track, you may need to start somewhere more basic to learn. The basis that a lot of people start is just simple books that teach beginner guitar scales, beginner guitar chords, or even beginner guitar songs. One of my favorite beginners book series, due to the effectiveness I have witnessed with beginners, is the Ernie Ball Phase Books. It may seem too slow at first, teaching how to play single notes can be boring, but it will bring your playing to whole new levels when you get deeper into the book. And then deeper into the phases of books until you are coming up with completely original songs. Especially if you are a true beginner guitarist looking for a new practice routine.
If you are less about learning the basics or the theory that goes into playing guitar and you just want to get out there to impress your friends as soon as possible, you may want to choose something more fun and enjoyable for yourself. For most people this involves playing their favorite songs. Think of your favorite band. Look up a tab book for your favorite album by them. If one exists, grab it, if not, move on to your second favorite and so on. All you will have to do when you get the book is simply learn how to read tab paper which should not take more than a few days if you consider yourself a fast learner. This may not be as effective of a method to learn guitar for in the long run because it will be harder for you to improvise or write songs, but it is the most fun of the methods listed so far.