A good website to pick up some tips from is
..:: PESFan ::.., though you have to join the forum to read the threads.
As for shooting, try and get your attacker facing the goal. If he has a decent enough shooting stat, he shouldn't blast it miles wide if you are more or less in line with the posts. Generally I find that you hit poor shots when you are rushed/pressured off the ball by defenders - so create space and only shoot when your player has a worthwhile opportunity.
As for defending, try and learn how to 'super cancel'. Using R1 + R2 when controlling a player, you have complete control over where they run (as opposed to the CPU choosing the most direct line to the ball). If you can master it, you can nick the ball off attackers without having to slide through them
Also I recommend you use the D-pad rather than the analogue which is a bit tricky.
I'm sure Rob will come forward with some tips aswell...