I want to have content (block of text) in a asset, and then use that same content in other assest without typing it in every time. I want these assests to automatically get this content and put it in the right column of the page.
The reason for this is that i sometimes i need to update the text and i just want to do it once and i want it to update every assest it is link to.
For example i want it to work like how pictures work, so if you change the picture, the picture changes in every assest it is link to.
How do i do this?
This is a core feature of Matrix: Just create a Bodycopy Div for your content and then link that Bodycopy Div to all the other pages in which you want the content to appear.
Because its the same Bodycopy Div, just linked in multiple places, when you change the content, it'll change everywhere its linked. 
To link an asset, just click its Icon in the asset map, move the target bar to where you want it to be linked, left-click and select "New Link Here". Remember that a Bodycopy Div must be linked under the "Page Contents" container of another standard page, for example.