Yep, like Lonnie said, be consistent over the long haul and you'll get where you want to go. If more questions pop up along the way, for sure toss them up here somewhere.
I was 6'2" and 170 in high school, so I kinda get where you're coming from. No worries, man.
You're 6'4" and 170-ish, so you're a tall lanky dude, but from your pics, your frame seems solid. Check out this article for some general advice about training for your build:
Make sure you're eating plenty. Three or four good meals everyday, plus a workout shake when you train. Try to base your food choices off the foods mentioned here:
Any more particular advice will kinda depen on what you're actually doing now. What does your current workout plan look like? What days, exercises, sets, and reps are you doing?