Pictures???

Hey. New at this blog stuff, but determined to learn. How do you put pictures in posts??? I can’t seem to figure it out. I see where you can put a link to a picture, but what about ones that are on my hard drive?? Thanks!!
Also, i would like to change the style, but i dont know where to go to do that, and I’m afraid to delete or add any code… Anyone want to tutor me??
Thanks!!
D