I would like to help you with the level-design but I have some stuff to do, but I can tell you what artists could need to be interested:

- Give em' information on how your level - style will be oriented (SciFi, Fantasy etc.)

- All artists could use information about the lighting in the level and what the main sources are going to be (sun, static\dynamic lights)

- Description on how to design it, more with models or blocks

- Information about camera positions so that they can better place details on the level and so that they dont have to put tons of detail everywhere ( less work and better for Framerate)

- General size information in quants or I think that 1 quant is about an inch so it can be in inches

there is much more that helps an artist organize the level and to get better results but this is just stuff that I think are useful and you should talk about it with your artist of course.

XTREME