I am a new quilter!!!! I don't prewash (I have 3 boys so I all ready have plenty of it) but I do starch and it helps a bunch with making sure I get a more accurate cut.
To find out what works best for you, why don't you pre wash some scraps, iron and sew see how you like it. Then don't pre wash, starch and sew and see what works better for you.
Like someone above said you will get many answers, its all about prefernce.
And by the way there is NEVER a dumb question. You can never learn unless you ask.