Perhaps the best (and cheapest) way of getting acquainted with single notes is by getting a few milliliters of pure essential oil. The difficulty with many notes, however, is that there is no single smell - e.g. Haitian and Javan Vetiver are quite different, not to speak of various treatments that can shape the original substance (there was a good thread on this regarding neroli in the men's forum). That said, my perfume suggestions would be:
- Ambergris: Creed Ambre Cannelle, the purest there is, perhaps even non-synthetic
- Labdanum: Valentino, Vendetta pour homme
- Leather: Aigner In Leather for a straightforward, no-nonsene smell of leather; Andy Tauer's Lonestar for a birch-tar (Russian) leather; Creed Royal English Leather for a sweet leather, Trumper's Spanish Leather;
- Vetiver: Villoresi's Vetiver for a direct harsh (beautiful) vetiver; Malle Vetiver Extraordinaire for a subtler rendition.
Can't help you on the florals.