Newb questions are okay in the newb section, but do keep in mind search works.
I typed "stock LS1 times" without the quotes and sorting by relevancy and got tons of threads: http://www.ls1tech.com/forums/search...archid=7821166
Mid to low 13's. The fastest ever run very high 12's. I think the top dog is like 12.8. M6 and power shifting (shifting without letting off the gas).
If you're running above a 13.5 or so, you either need some practice driving or your car needs a tune up. I ran a 12.98 with just header into cutouts and a lid and $100 street tires (Sumo's). It was my first and only trip to the track ever. Granny shifting.
EDIT: And, in answer to your other question, I would "launch" at about 2,000 or so to start and quickly release the clutch. But, I'm no expert. Tire spin is bad
, as is "bogging." You want to barely
chirp the tires.