Newb question on jump building

[Ecleland]

New to the forum and getting back into mtb's. I live on a small 8 acres with a few steep hills and a pond, some trails, and several unique landscapes...
I'm wanting to incorporate a few jumps and some technical features to my land for myself, and my ever growing baseball team of kids.
Is there a way to judge the height and spacing of ramps?
Does anyone here have some suggestions for YouTube or DIY instructions on course building?

Thanks,
E