whats the easiest way to limit bone rotation. i see something about euler but not sure where or how to apply. am i to do it in smart skin mode?

Use an euler limit constraint to limit the rotation using the min/max settings within the constraint.

In a pose, action or chor, right click on the bone you want to limit and select new constraint.

rotation limits are a constraint you apply in a pose window. make a new ON/Off pose. Select the bone, then NewConstraint>Euler limits

okay im getting it. but if i want it to be permanent? im trying it in smart skin mode and im getting a bit of a result. is this correct to do in smart skin mode?

No. You do it in a pose to make it permanent. Once the pose is created, turn the pose ON in the models user properties.

here i have used smart skin mode and applied the euler constraint. you can see my settings. and in the action window the arm bone is holding. i assume that if its working in the action window then maybe it will be ok in a chor. will have to test. being really ignorant when it comes to rigging i hope this is at least one proper method to go about it....your advice would be welcome.

okay ill try it in a pose as well. thanks