I have been meaning to put together a FAQ link for PL/SQL, but cann't seem to get around to it.
If you are a PL/SQL beginner, you might want to visit here.  
That is where you can see all official ORACLE documentation for all things ORACLE, including PL/SQL.

• Find parent or child nodes in a DAG
• HQ in a data warehouse environment
• Counting nodes in branches
• The basics...
• hq with name look up
• How do you copy a tree?

• The basics
• The restrictions
• Bulk bind records with PL/SQL record type
• Bulk bind reocrds with table of object
• Bulk bind across database link
• Forall with RETURING BULK COLLECT
• Bulk bind attributes and the LIMIT clause
• Bulk bind exception handling

• "TABLE" function
• Table function inside a TABLE function
• "TABLE" function and table of records type
• Append one collection to another?

• Bind a record?
• Dynamic SQL with bind variables
• Dynamic SQL with bulk bind
• Dynamic SQL with Forall
• Dynamic SQL with ref cursor
• Dynamic SQL with the IN operator

• Passing a ref cursor
• Passing a PL/SQL record?
• Passing an array?

• Why bind variables?
• Bind variables and dynamic SQL

• FAQs
• The basics
• The windowing clause
• Interval literal in the windowing clause
• Bridge the gaps - in bucket_width
• Row_number() and WITH clause
• When NOT to use Analytic function

• A non-pipelined table function
• PTF with refcursor

• Use FBI?
• Use Deterministic Function?
• Restrictions

• Full outer join
• Conditional outer join
• Outer join and index
• Slightly strange outer join

• The basics
• Merge and exists cmparison
• Conditional Merge

• DBMS_OUTPUT within functions
• Package state
• Calling remote procedure with "commit" and "OUT" parameter
• Calling remote function with "commit"
• Mutating table error
• DML on join views
• Get GMT with external procedure
• Deterministic function
• Forward declaration
• Circular and self referencing
• Passing parameters by reference