My 8 1/2mo DS is just starting to get a bit unpredictable at the moment with his naps etc, having previously been quite a creature of habit (not my doing at all). Routine usually...
Up 6-7am
Nap 9am (usually 1 1/2hrs)
Nap 2pm (probably only 45 mins, sometimes 1 1/2hrs)
Nap 5pm (45 mins, though doesn't always have this nap)
Bed 7-8pm
Sometimes his naps are longer, and times can vary quite a bit depending on what we are doing. Today for example he had 2 1/4hr at 9 and then 45mins at 4pm. Morning nap almost always in his cot, after lunch could be in buggy/car/my arms/cot and later nap if he has one is usually in the cot.
I stick to NO particular routine, just work with when I think he is tired and have never tried to do any different. I never wake him from a nap unless his late afternoon one is going past say 6.15 or so, even then I sometimes let him sleep. He is always fine to go back to bed as soon as he has had tea, bath and bf, even if thats 30 mins after he woke.
My friends baby will sometimes have 1 30min or so nap a day and sleeps similar hours at night. They are all SO different, almost not worth comparing. I have a very sleepy baby who is a nightmare if he doesnt nap! It has its good and bad points 
HTH