Even if you have always used a computer to do your genealogy, chances are you have paper records. Photocopies from books, records sent from a courthouse, photos, old letters... you get the idea.
While having the original paper document is great, you should also digitize your records and sources, and find a place to upload them online. You will want to have a back up of your records. And it makes it easier to share.
So, buy a scanner, or even a decent digital camera and digitize your stuff.