Skip the valerian root...
Take "one" 3mg melatonin tab 30-60 minutes before you plan to go to sleep. If you take it any earlier than that, you'll pass the point of peak effectivity and it won't help. If you take any more than that you're going to feel groggy in the morning.
Also, melatonin is something that isn't designed to be taken for weeks or months on end. So you should only take it when you feel really wired before going to bed. Otherwise you'll end up building up a tolerance and it won't work for you at any dosage.
You should probably figure out why you're having so much trouble sleeping and solve your problem naturally rather than introducing sleep aids. (e.g. give yourself at least four hours between your last meal and bedtime, go do a short run 5 hours before you go to sleep to help your system supress itself in preparation for sleep, etc...).