I think Instant Weather Forecasting is good to have, as it has photos of a large number of different conditions. However, for a better
understanding of the weather I would strongly recommend Tom Bradbury's
Meteorology and Flight.
Denis Newton's Severe Weather Flying is an absolute must for any IFR pilot's bookshelf. But it does deal predominantly with Thunderstorms and Icing from the pilots point of view, and so may not be of so much interest if you're just looking to interpret model charts to see if the weather is suitable for a VFR bimble.