Table hint basics

SELECT columnlist FROM myTable WITH (TABLOCK);

Generally avoid table hints and let SQL Server manage locking.
Exact behaviour depends on the isolation level.

• TABLOCK - Shared table lock
• TABLOCKX - Exclusive table lock
• NOLOCK - Like the READUNCOMMITTED isolation level.
• UPDLOCK - Use update locks
• XLOCK - Take exclusive locks

Full list at MSDN