To answer such a general question, I have to say lookup the following in Books Online...
Bulk Insert
BCP
BCP Format Files
Linked Servers (for text files)
OpenRowSet
DTS
SSIS
OSQL
SQLCMD
--Jeff Moden
RBAR is pronounced "ree-bar" and is a "Modenism" for Row-By-Agonizing-Row. First step towards the paradigm shift of writing Set Based code: ________Stop thinking about what you want to do to a ROW... think, instead, of what you want to do to a COLUMN.
Change is inevitable... Change for the better is not.