Useful System Procedures :

sp_help ==> To get a table / object definition

Example :   EXEC sp_help object_name

sp_helptext ==> To get the procedure / view text.

Example :  EXEC sp_helptext Proc_name

sp_helpindex ==> To get the index information on a table

Example :  EXEC sp_helpindex Proc_name

sp_helpconstraint ==> To get the constarints on a table

Example :  EXEC sp_helpconstraint Proc_name

sp_depends ==> To get the dependencies on table / procedure / view.

Example :  EXEC sp_depends object_name

sp_spaceused ==> To get the size of a table or database, if you didn`t pass any input it will show the size of the current database.

Example :  EXEC sp_spaceused table_name

sp_helptrigger  ==> To get the triggers on a table

Example :  EXEC sp_helptrigger table_name

sp_rename ==> To rename database objects and columns.

Example : EXEC sp_rename 'table_name' , 'new_table_name'
     EXEC sp_rename 'table_name.column_name' , 'new_column_name'

sp_tables ==> To get the tables with the name like a given syntax / pattern.

Example : EXEC sp_tables '%user%'

sp_stored_procedures ==> To get the stored procedure names with the name like a given syntax / pattern.

Example : EXEC sp_stored_procedures '%user%'