Springs and shocks

[dodgefsu]

Can anyone explane the adjustment on my springs and shocks...
I have gotten several theorys on right and wrong setup.
For example when I jump and land it feels like I am bottoming out.
and whoops it is really hard to stay on the bike ,, not good enough yet to stay on top of the whoops.....
Do I adjust the spring out or in..." out meaning make the springs l o n g e r ,
or maybe upgrade to something better....
I ride a honda 400ex and ride at home, croom, and some real flat smooth land.