There have been SO many sleep studies done and almost every one of them has a different outcome as to how much sleep you should get every night. Some say no more than 7 hours, others say no less than 5 hours, some say you really only need 4 hours... what to believe?
I personally believe that somewhere between 6-8 hours a night without naps during the day is a good amount of sleep.
It really all depends on physically activity level, age, work, lifestyle, etc.
Don't deprive yourself sleep if you don't have to. If you are a mom or dad of a newborn then you really don't have a choice but to lose sleep, or if you are sick with the flu; then you really don't have a choice. If you want to catch a TV show that airs at midnight but have to get up at 6 am to be at work at 8, then you have the choice of missing that show or missing out on sleep.
Sleep is so important to our bodies, it helps us focus, it aids in weight loss, it helps with energy levels, and just makes us feel better.
I am not a napper, because it does interrupt with my nightly sleep. I also don't have time to nap during the day. I think napping is for the select few, new parents, night shift workers, kids, and the elderly. It usually will interfere with night time sleeping patterns so I don't recommend it unless needed.
If you cannot sleep at night try a few things; warm bath, hot beverage (herbal tea, warm milk, or warm water with lemon & honey), read instead of watch tv, soft music, or a white noise machine. If all that fails, then talk to your doctor about adding a natural sleep aid to your night time routine: Valerian root, Chamomile or Melatonin.