Hi, welcome to Basenotes!
For me, the best place to start is with Michael Edwards' online Fragrance Directory.
Click on 'Fragrance families' on the lower left of the screen and you will bring up a list of the fragrance families. Next, click on the plus sign to the left of the family you wish to explore. This brings up the four subfamilies within each major group. Finally, clicking on one of the subfamilies will bring up a comprehensive list of the current fragrances within that classification.
Michael Edwards' 'Male Fragrance Recommender' and 'Female Fragrance Recommender' are also very helpful if you are trying to classify a fragrance that is not listed in his main Fragrance Directory.