Have a look at this earlier thread
for lists of things to buy - if you want to do entirely natural perfumery you’ll need to ignore my suggestions about aroma chemicals but there are some great ideas about natural materials to start with there too as well as some good starting advice.
As far as books are concerned, most people interested in natural perfumery rate Mandy Afftel’s work highly, so you could have a look at that. There is however no such thing as definitive or comprehensive in this business so you’ll probably want to read around in more than one area.
I would recommend looking at The Perfumer’s Apprentice
site for lots of good advice and ideas, pre-designed starter kits and a the full training advice notes from Jean Carles
, which many people also find very helpful - he wrote from the standpoint of using the full range of materials, but the principles are the same if you restrict yourself to the subset of natural ones.
I hope that helps.