In the Main arena, the gun points all you get for rockets and dive bombing.
In heavy bombers, you have a bombsight (F6) that you can calibrate for accurate level bombing. Read more about it on
Net Aces.
In the Training Arena (and offline) theres a Lead Computed Gunsight for bombs/rockets enabled. as soon as you select them, you get a green cross, showing you where theyd hit of released. You can use that to assess your aim.
When dive bombing, make sure your angle is steep enough. Never use *rudder* to correct your aim, as bombs/rockets will follow your actual flight path and NOT the longitudinal axis of your plane. More details on JABO also on Net Aces, under the "Bombing/Jabo" section.