If you're a skinny runt, then I can give you a work out and diet routine that
can allow you to gain roughly 20 lbs over the summer. (The program aims for a 20 pound weight gain.) However, it is exceedingly difficult for someone who's new to it and you have to be extremely determined to keep on track. If you are skinny, chances are you aren't used to eating right and so you'll be forcing your metabolism to change by eating a lot. You'll need access to a lot of food. You can't get lazy and skip days. You'll need access to a gym.
Alternatively, I recommend visiting
Bodybuilding.com - Find Bodybuilding Workouts! . Look through the programs, sift through the articles and read reviews of personal workouts to try and find something that suits you.
As a side opinionated note: only use supplements if you're really, really desperate. You definitely don't need supplements when you're starting out and once you stop using them you'll be losing your hard-earned fitness fairly quickly along with energy.