Oracle Database Discussions

We are preparing to implement Data Warehouse on Oracle 11g R2 and currently I am trying to set up some storage strategy - unfortunately I have very little experience with that. The question is what are general advices in such considerations according table spaces and block size? I made some research and it is hard to find some clear answer, there are resources advising that block size is not important and can be left small (8 KB), others state that it is crucial and should be the biggest possible (64KB). The other thing is what part of data should be placed where? Many resources state that keeping indexes apart from its data is a myth and a bad practice as it may lead to decrease of performance, others say that although there is no performance benefit, index table spaces do not need to be backed up and thats why it should be split. The next idea is to have separate table spaces for big tables, small tables, tables accessed frequently and infrequently. How should I organize partitions in terms of table spaces? Is it a good idea to have "old" data (read only) partitions on separate table spaces?

Any help highly appreciated and thank you in advance.