I also search table sys.sql_modules, which contains the code for all sys.objects members of type P, RF, V, TR, FN, IF, TF, and R.
If you want to check for use in a job step, also check table sysjobsteps (msdb.dbo.sysjobsteps), column "command".
SQL DBA,SQL Server MVP(07, 08, 09) Prosecutor James Blackburn, in closing argument in the Fatal Vision murders trial:
If in the future, you should cry a tear, cry one for them [the murder victims]. If in the future, you should say a prayer, say one for them. And if in the future, you should light a candle, light one for them.