I'm 14 years old, real skinny weigh 108 pounds 5'4 tall i think... and i want to gain more muscle so i wont look so skinny but i don't know where to start. Is it safe to lift weights at my age and height?
Have you taken a look through the young athlete section yet (http://training.fitness.com/young-athlete-development/)? I would suggest that you read through the information in the sticky threads. It is usually safe for teens to lift weight, but it's very important to focus on proper form, starting off with very light weights, and only progressing really slowly to heavier weights.
Do some reading and come back with some questions!