To make a map in Minecraft, you'll need one compass and eight pieces of paper. Both the paper and compass can be crafted with raw materials that you'll dig and.
To create a custom map, you'll first need to download a map editor program. There are many different map editor programs available, such as MCEdit and WorldEdit.
Each zoom level of maps has a grid that all maps now align to. The top left corner of each map now aligns to the (x,z) coordinate (-64, -64) +- (m,n)*size.