Workout routine for thin female?

HI there, i am a 5'2" 21 year old female. I have a very thin built and a fast metabolism. I am looking to gain weight and tone my body without bulking up- thin built women with bulging muscles is not good for the eyes! I was wondering if there is any websites or youtube personal trainers/videos that would help me with my goal- gain muscle mass without bulking up like a body builder. I would like a wider physique- my arms are very thin and my whole body has no shape. Is there any work out routine that would allow me to create the look of a wider hips and smaller waist so that when I put on my bikini this summer I dont look like a 2 year old? Suggestions please?!