Wallpaper condition

[Isotypeswitching]

I have just bought a house with reasonable condition wallpaper in the lounge, but I'd like to repaint. The paper has some bubbles near the seams in places and is really badly painted in around light switches etc but it otherwise looks OK. What would be the best way to fix the bubbles and how should I best prepare the walls for painting? Thanks!

 

[He who knows]