Eating too much before bedtime not only doesn't help you fall asleep faster but is also not healthy. Have a light snack 2 hours before sleep time the latest.
This advice has simple explanation. Your organism stays awake digesting the food, so even if you fall asleep part of
your body is not "sleeping" and overall you still have less effective sleep which is not restful. You will need more
sleep which in turn will not let you wake up easily.
Same applies to drinking lots of water, cola or any other beverages - you will feel discomfort and
will have to get up to urinate during the night. If you feel thirsty put a glass of water near the bed
and take a little sip from it from time to time before you fall asleep or when you wake up during the night. What's interesting though, Jon Rhodes from HypnoBasters told me that native indians used exactly the opposit trick - obviously they didn't have alarm clocks so instead they drunk loads of water just before going to bed. That way they would wake up early as they would soon need to relieve themselves!
Please note that going to bed hungry or thirsty is not good either and can be just as disruptive to sleep as going to bed too full.
Having very light snack or glass of milk will help you ease the hunger. Check this Yahoo!Food article
to decide what to eat for a good sleep:
Top 10 Foods for a Good Night's Sleep from Yahoo!Food.