painting over wallpaper

[doirin]

my father wallpapered over new plaster{after 2 weeks drying} and then proceeded to paint over this(following week), he is left with the joinings of the paper showing and cracked. is there anything he can do without ripping the whole lot off?(All the other walls were papered so he wanted to make it look even.)
Hope you can help with this
doirin

[thedoctor]

Run over the joints with some fine surface filler on a pallate knife, then sand down very lightly and repaint.

[usaf]

hi i am painting my room for the first time and know nothing about it .walls are covered with textured paper ,and its in good condition ,edges are perfectly intact and i dont mind texture in it.what would be the easiest way to paint it .please tell me the best paint type as well for it and how to prepare walls before applying paint on it .thanx alot