I'm a new quilter also. Recently finished my first quilt.
Some things that I learned (some the hard way)
Pin EVERYTHING until you feel that you don't need to.
Pay close attention to the direction that you press seams.
When pressing, hold the piece of fabric that you are pressing TO up in your hand and press away from you ( right side up ) This helps eliminate what I call "overflap". ( someone else may be able to explain this better than me ).