Well, no I'm not the Queen of Organizers but now and then I do come up with an idea that works.
I take a three ring binder (big one in my case, but you could use a bunch of smaller ones)
I get those plastic sleeves which have three holes in them and then I place my warranties, sales slip and user manual together in a sleeve.
I put them in alphabetic order, but you don't have to.
I keep the binder in a cupboard that is easily accessible. Then when something goes wrong, breaks down or what ever...there is the info on that item.
Even my DH patted my back on this one
Tootsie