i know this is your first time and some of us may be animated... cutting off the top is one option and it may not be the best option. i don't have time to type, but if you go to google.com and search for the method called 'no stress training' on cannabis plants, (also called NST) that will help you ALOT on your bud size and all. please post back if you have not found any good info on NST. you can get ALOT more out of your plant and NOT have to cut it anywhere. take care