child post under category parent

hello
I have been looking for answer few weeks and I just cant find it;/

what I would like to do:

I have category list on my page.
when I enter category I would like to have Post’s list only for that parent witch links to actual post.

example:

I have 3 parents categories :

parent 1(link to all child post from that parent only )
parent 2(link to all child post from that parent only )
parent 3(link to all child post from that parent only )

when I enter any of then 4example (parent 1)
I see only list of posts from that parent.
child 1 (link to post)
child 2(link to post)
child 3(link to post)

what and how I should edit to get something like that ?
any idea how I can do that ?

at the moment Im trying to make blog with Online movies and I really have no idea how I can get list of episodes as a list on parent category post;/
plz 4 help