What...? Vintage 1990...?

IMHO, it's pretty much your own personal tastes along with trial and error. I thought I'd like Onyx based on the tobacco...nope. I didn't think I would like 5 Vegas Gold...wrong again because these are great.
 
Try this, buy these cigars and it will be your best bet in guiding you to what you like, each is a perfect representation of typically qualities from a given seed.

Connecticut Ecuador: Montecristo White Label
Connecticut Connecticut: Cusano Hermanos Vintage
Sumatra Ecuador: La Aurora 1495
Sumatra Sumatra: Romeo y Julieta 1875
Connecticut Broadleaf Maduro: Ashton maduro
Havana Corojo: Camacho Corojo
Havana Criollo: CAO Criollo or Camacho Havana
Brazilian Mata Fina: CAO Brazilia
Cameroon: (here you have to try several brands as cameroon is very different depending on the grower) 1. Fuente 858 2. Leon Jimenes 2001 Cameroon and 3. Perdomo Tradicion Reserve Cameroon F


Smoke 2/3 of each cigar. When you are done, take teh ouside leaf (wrapper off and save it) Compare the left over wrappers. See the differences between seeds and regions. Burn it and smell the aroma. I would keep a log of the tastes of the cigars and wrapper characteristics. Once you figure out which of the above you like, call you cigar guy (Tim or Donny) and tell them what you liked about it.

As far as how do you know what you are buying, that is difficult since there are no governing standards in the tobacco industry. People can name things whatever they want. Your best bet it to check with us when you are making your purchase or ask us what type of cigars you like or what type of wrappers and we will fix you up.

On the cigar.com brands pages we try to list everything by seed and country. However, Natural is usually connecticut or habano.
 
Note that the above I posted is just a guide. There are other seed/region combonations not listed. I just gave the most common. The above would account for 95% of cigars made.