In my younger days I spent a good 5 years of my life as an avid baseball card collector. About 15 years ago I put them all in a box and just recently thumbed through them. I found several that I thought may be worth something, but am having trouble finding a resource. I know as a kid I used to purchase a price-guide magazine, but the name of it escapes me. Does anyone know of any reliable resources, in print or online, for card value appraisal?