The video above demonstrates what you need to define where you deal gets imported into Pipedrive. This can all be controlled simply by designating a column in your spreadsheet that will be associated with the Stage option during your import. This also determines which Pipeline the deal goes into if you have multiple pipelines.
You don't need to worry about the names of your stages matching, or specifying the name of the Pipeline you're importing into. Instead, once you select Stage during your import, Pipedrive will present you with a list of all of your stages across all of your pipelines. You can then drag and drop the names in your spreadsheet to the appropriate stages in Pipedrive.
It's as simple as that.