Such as these gentlemen here http://artofmanliness.com/2011/03/14/the-napping-habits-of-8-famous...
Especially this one
I would like to see if there is any trustworthy and credible info or books on this?
Science Friday has a section on sleep.
First you need to be getting the amount of sleep your body needs in the night. So are you getting 7-9 hours at night?
When I was younger and not in an office during daytime working hours I would take naps when my schedule permitted during the day. I don't have any solid evidence to support this but personally I had the most success with trying to time my nap to sleeping cycles. I heard somewhere that you sleep in 3 hour cycles. If I was able to lay down and get a 45 minute nap or a 90 minute nap I would wake up refreshed and ready to go. If the nap was 30 minutes or an hour there was no telling how I would feel when I woke up.
This mentions the cycles and my numbers sort of fall in line with theirs.
On the rare occasion where I am exhausted I will go to me car during my one hour lunch break to take a nap. I drink some caffeine then set my alarm for 45 minutes and recline my seat back. I get a nice little power nap and the caffeine has kicked in at this point and I usually wake up feeling better than when I went to sleep.
Finally someone understands what I'm talking about.