What would be the best way for me to get built?

I am a junior in high school. I was never a serious athlete until last year. Now I am a full time runner. I run cross country in the fall, keep running in the winter and run track during the spring. I am going to keep running during the summer. But as I am a distance runner I have never really had to train with weights or muscle training. Now I want to start building muscle over the summer, but I'm not sure how to start. I have a decent frame and a medium build body but that is just because of genetics. Last time I checked I could only bench 155. I want to start a workout regiment that will equally train my entire body. If anyone else has any muscle building routines they could share that would be greatly appreciated.