There are a lot of questions surrounding what is the best method of starting out a project in Revit MEP if the Architect or Structural engineer has sent you a Revit Model.
When starting your project with another Revit Model, you will start out first with your own "New" project template within your software. Then you link in their file by going to the Insert Tab > Link Panel > Link Revit and link in their Revit model. Veryify that your position is set to "Origin to Origin".
From the Project Browser or from an Elevation view, you will delete all but the current view/level because you want to work from their levels not the default levels in your project. You will get a warning that other views related to the ones you are deleting will be deleted as well, this is ok so click on the OK button.
After linking in the model, go into an elevation view so you can see all of the levels. You will be able to tell which is your levels and which are the links levels, because when you select on the linked models levels the entire linked model will turn red.
Now you will need to copy and monitor the levels into your project. From the Collaborate Tab > Coordinate Panel > Copy/Monitor > Select Link. Select on the linked model.
From the ribbon click on Copy from the Tools Panel and put a check mark next to Multiple on the option bar.
Using a crossing window or holding down your control key select on all the levels. When you have selected on all of the linked models levels click the Finish button on the Options Bar.
Go into options and on the Levels Tab, set reuse matching levels to reuse if within offset. (that way you don't have to delete the original levels)
Click on the Copy/Monitor tab to be able to click on the green check mark to Finish. While you are selecting on the levels to copy into your project you can also select on the grids that you will need as well. NOTE: Do not copy monitor walls as this has caused a lot of issues with models and will give you an extreme headache.
Now that you have the levels copied into your project you will then need to create the plan views. From the ribbon you will go to the View Tab > Plan Views > Floor Plan. Select on all the levels and click the OK button.
Here is a WikiHelp video on linking models that covers how to Link Models in Revit.