Binary is probably the best - some .DOC files are not just text, they include binary data as well. If you store them in a text field, you may get problems later because of character sets / translations.
Storing them as VARBINARY(MAX) isn't difficult - all you have to do is use a parameterized query, just like you would have to do for a text file:
using (SqlConnection con = new SqlConnection(strConnect))
using (SqlCommand com = new SqlCommand("INSERT INTO myTable (myFileColumn) VALUES (@DATA)", con))