Everyone had their own naming standards for cubes, dimensions etc but I have a few that I try to stick to when building applications
1) Don't use Month and Year as dimension names because these are reserved words in TI and it gets frustrating having to rename your variables each time. I tend to use Period and FiscalYear for GL type data.
2) Try not to have spaces in your names. Instead use underscores or capitalisation.
3) Don't name your dimensions the same as your cube e.g. a cube called Programmes with a dimension called Programmes
4) Make the names of the dimensions meaningful to users. Do not use Relational table column names.
5) Almost every cube you create will have a Measures dimension. Try to have the dimensions with a naming standard e.g. GL_Values, HR_Values
It would be useful if other people comment their ideas for naming standards as well.