well, my advice would be to experiment for a day or so about when you're able to study best.
For example, try the studying before school, they say it helps cause its the first thing that gets into your head so its sticks- when i do early hours i study subjects that i have on the same day at school and one that needs understanding so in class i'd have everything fresh in my mind...
Memorising subjects in my opinion would be best in the evening because you'll be tired so you're brain might not be able to comprehend complex material but it sure will memorise.. but test it out anyway cause it could be the opposite for you
also, subjects you're having trouble with do more hours of or subjects that might need a higher mark to scale you- but that's a bit dodgy
hours per day: as much as you can handle - there is no limit to greatness
In terms of how long each of your study periods go for, some people can sit 3 hours straight (like me- sometimes) and others can't sit for half an hour so test your limit and keep studying till you pop
then you'll know how long your study periods should be.
breaks: depends on how long you've been studying for.. an hour of study could give you bout 15- 25 min break?
anyways, hope i helped.. good luck with everything