Depends on what you have now.  Desktops are pretty easy to upgrade; laptops not so much.
Memory, hard drives and peripherals can be put in, provided there's space for them, on desktops

Laptops - mainly the only upgrades you can do are memory; sometimes the Hard drive, and a few cards can be added.

BTW - isn't that Shatner from the Twilight Zone as your avatar?

I wish I'd said that.. The Staircase Wit

anahl nathrak uth vas betude doth yel dyenvey..;)