Weight program for summer?

Im 16 years old. And i really need to start lifting weights. Im super scrawny right now. I swim and i didn't make state cut by a second and my coach said i needed to start lifting weight. i can bench about 90(sad i know). im wondering what i need to do for benching and what not that will get improvement quick. I'm fairley free and can find time to lift weights any day. I have a free membership to a gym (i work there) and my friend has a gym in his basement. so its just merely a question of what should i be doing to gain some bicep and more muscles.