Change read more button

Hello everyone! i just start coding on my new website but i got a question about read more button:

[img]http://i.imgur.com/Ie5itzX.gif[/img]

I want to have the read more button always sticky on the border bottum of the article. Can someone explain where i should start, i know how to CSS but i just can’t figure it out.

So can i take little of your time to help me out, i would really appreciate if somebody could help me.