Do comic book effects apply even if they've been put in a comic book stand?

Yes. The Perks remain even if you sell the books - which I did some of the early ones, unfortunately.

I believe that once you've read them, the effects apply, I keep mine stored in a trunk in my house in Sac Hills. It would be nice to know if you needed to keep them on you for the effects to work.

edit: Thanks BrewerGeogre for clearing that up.