Excellent first post there, Bourbonlady. Welcome to BE. I'm not here very often anymore, so let me reccomend this quartet.
1) Knob Creek - 9 years old & 100 proof
2) Evan Williams Single Barrel - 10 years old & 86.6 proof
3) Eagle Rare Single Barrel - 10 years old & 90 proof
4) Larceny - a marriage of 4+ year old barrels to give a good solid 6 year old flavor profile overall & 92 proof. Larceny is a wheated recipe bourbon or 'a wheater'. I like it quite a bit.
There's a lot of flavor profile differences here between these four. You could add in Four Roses Small Batch if you'd like to have five, but those four are plenty to educate your palette. These are all very well crafted and excellent tasting bourbons, but they all have very distinct flavor differences you can teach yourself to pick up on by compairison tasting.
Forget the fact that two are single barrels. Just think of them as 'micro-batch' as a single barrel is the smallest batch you can have!
Zero in on and isolate the most common bourbon aromas and flavors. Yes you must be able to do both. Things like vanilla; char, oak, and caramel. Read some of my old tasting notes for example, and see if you taste and nose some of the same things.
You will need 4 identical glasses. There is no subtitute for good glassware. Glencairn are the most common. They are good nosers; affordable, and easy to come by.
I hope this helps you get off to a good start. Enjoy your pursuit of bourbon knowledge.
imasaintbunghole