crossover cable : If you are connecting two same device like two laptop or two router you will used this/
Straight Through: But if you are connecting laptop to router or pc to switch ie. different device than you will need Straight Through cat5 cable.
This is what we expect in theory ..
But this is not what happen nowdays . due to advancement in technology new equipment automatically detect the type of connection . So crossover would work fine for you.
And it's not the age of cable which matters but the age of equipment that matters. Anything which is 3-4 years old will work fine most probably.
P.s I myself used straight through cable (which was meant to connect pc to router only) to connect two laptop for file sharing and lan games. So It will work other way round too.