SQL performance tuning..

[Rick_Creel@AONCONS.COM]

The SQR I am working on is in a PeopleSoft environment, specifically PeopleSoft
Projects.
PSoft Ver 7.53
Oracle Ver 8.06
SQR Ver 4.34

I am joining the PROJ_RESOURCE table (which has over 3 million of rows of data)
  to the PROJ_ACTIVITY table
(which has just over 127,000 rows of data).

For purposes of efficiency, is there a "rule of thumb" as to what sequence to
specify the table names in the "FROM" clause?
Do you say
FROM PS_PROJ_RESOURCE PR,
      PS_PROJ_ACTIVITY PA

or
FROM PS_PROJ_ACTIVITY PA,
        PS_PROJ_RESOURCE PR

or does it matter?

In the WHERE clause, what about the sequence of the keys for each table,
especially the keys that are
used to join the 2 tables?

The SQR I have works, but it is slow as molasses in the winter!  I need to
fine-tune the queries to make them
as fast and efficient as possible.  I hate to admit it, but I have no clue how
to optimize SQL code and have never
been given any training in how to optimize code.

Thanks for any help/advice!