Different Lead Types

Different Lead Types

I have two types of leads, buyers and sellers.  I set up a set of questions (not done) for the seller leads and have yet to set up for the buyers.  When I or my assistant start to fill out a lead sheet, how do we differentiate between a buyer or a seller lead and keep the two types of leads different.  

Also, can I scale the lead types in the future for different types of leads?