To get the month name from a date in SQL Server, you can use DATENAME Built-in Function:
SELECT DATENAME(mm, GETDATE())
SELECT DATENAME(mm, '2013-08-20 11:46:26.441')
SELECT DATENAME(mm, '2013-07-11')
If you want the result in a different language than the login default language, use the SET LANGUAGE statement with the name of the language from the sys.syslanguages System View:
SET LANGUAGE German
SELECT DATENAME(mm, '2013-07-11')
SET LANGUAGE Spanish
SELECT DATENAME(mm, '2013-07-11')