A slab serif font is characterized by thick, block-like serifs on the end points of each character. For example, the small horizontal lines on the "N" in Novecento are slab serifs. Above are three of my favorite free slab serif typefaces, all available for personal and commercial use on FontSquirrel.com. Find Cyntho Slab here, Josefin Slab here, and Novecento Slab here.
Don't forget to drop by Design Fixation again... I'll have some beautiful packaging and gift wrap inspiration for you later this week!