Young babies also prefer black and white, high contrast images to colour graphics. You can now buy lots of black and white baby books, mobiles for the cot and other black and white contrasting play items.
The following link is a great resource which I use lots within my baby groups when working with parents and babies together developing early language skills through play. The pictures are so striking that I use them on home made building blocks.
Watch your little ones reactions while you talk to them : )
My building blocks are made from a dice template. A3 versions make great dice for babies. This one is from www.sparklebox.co.uk. Make sure you round the corners to make them safe. Fill with shredded paper.
If you want to make a different variety when they get older try making a set with family members and pets, favourite characters etc.