I am 15 years old and have never done a "proper" workout in my life, I am almost 6 foot tall and weigh about 135lbs. Having read other posts i believe i may be an "ectomorph."
I need help devising a program and have no equipment and limited funds - due to my age. I would appreciate any advice. Thanks.

Try trainforstrength.com

Try asking your parents or someone to get you some dumbbells, a barbell and a bench (or a gym membership).

To start off, get some information.

Routines: http://www.realfitnessworld.com/Routines.htm
Exercises: http://www.realfitnessworld.com/exercises.htm
Cardio: http://www.realfitnessworld.com/Cardio%20Regimen.htm
Diet: http://www.realfitnessworld.com/Diet%20Peter.htm

That's all I can really say for now.
If you have questions, we have answers.
GOOD LUCK.