SQL & PL/SQL

Hi,
i need an advice on how to trace very long PLSQL as iam new to my company and the business is very new to me , i am a very good developer using Developer suite , but my weak point is tracing very long packages and undestand them ,

i want to trace a Procedure that have a LOT of lines of code and it calls many other packages, i really need to be quick in undestading what this procedre is doing as i should solve my problem in appropriate time

i am using dbms_output.put_line for tracing, to know what is the path that is taken and the variable values but i think i need a totaly different approach


also there are some sqls in this system that is very long, some of them is joining more than 10 tables at the same time, any hint to understand what this sql is doing?

any help is appreciated.