You have different options using a workflow from ArcGIS to Civil 3D. You can export to CAD using the ArcGIS toolbox. I haven't used this much, and haven't heard good things. The other option is to save your vector files as a shapefile, and then switching Civil 3D to the Map 3D toolset you can import shapefiles into Civil 3D with their Attribute data (called object data in Map 3D). You can also use attribute information to import the vector data onto different layers. There is a few extra steps if you want to transfer Attribute / object data to the different properties. For example, elevation might be stored as an attribute but with Civil 3D you need to set the elevation property. There are a number of examples on how to do this across the web. The final option is to directly connect to a database. The last version I was using (2006) was only able to connect to an Oracle database, but other options might have been added.
Note, TINs created with ArcGIS are not directly transferable to Civil 3D and will need to create contours and then bring them in that way.
I can't comment on a 3ds workflow.
Hope that helps,
David