Date dimension should be fairly easy going for you as the Hierachies are a lot more natural.
If you are able to i would recomend downloading the AdventureWorks cube from Codeplex as this has a data hierachy already setup that you can get ideas from.
also make sure you setup the date hierachy as a Time Dimension (click properties on the hierachy name)
and also set each of the attributes to the correct type (month, year , day etc..) as this will allow you to do time-based calculations.
And also you will need to sort out the order so that Month name and Week Names are sorted by the Numbers rather than the word otherwise the ordering will be out.