Can partitioning help speed up inserts on a very large table?
Short answer: yes it can help, because it's theoretically instantaneous. You would insert your data into a staging table with the same definition as your main partitioned table, and then switch it into the partitioned table, which is a metadata operation (schema lock).

Long answer: it might make performance suffer over the long run to have such a large table, and unless you move to later versions of SQL Server, statistics updates are quite difficult to manage.

If this is a read-heavy table, I'd consider using view partitioning instead. Each month (for example) would get its own table, with check constraints on a date column to help the query optimizer know where the data is physically stored, and a view over the top of that:

SELECT col1, col2, col3, col4 FROM period201501
UNION ALL
SELECT col1, col2, col3, col4 FROM period201502
...
SELECT col1, col2, col3, col4 FROM period201608


(or whatever). Then your metadata operation is the update of the view, as opposed to the switching in of the partitioned table.