Well as I am no blenderer, I can't really help you out with tuturials in specific.
but I can give you some good advice:
Experiment, it works really just take an shape and try out what is possible by using the Lattice Modifier tool only
or something alike. I've been doing it for the past few years now in maya so I can tell.
anyway, maybe these tut's come in handy:
Manual/Lattice Modifier - BlenderWiki
Tutorials/Lattices/ShapingFork - BlenderWiki