I just want to crochet an amigurumi doll, but I can only find patterns for animals.

I really like this kind of body shape:
http://ny-image0.etsy.com/il_430xN.82638384.jpg

Does anyone know where I can get a basic pattern for this sort of thing? I want a base so I can customise the doll.

This Website offered the basics of how to. And lets you use your own colors to customize. All that they show is the most basic patterns, and ideas of what can be done with them.

http://crochetme.com/amigurumi-dude

I hope that this will work for you. The pattern seems pretty straight forward.