Each time I'm at my LHBS I ask if I can taste a few grains. They don't mind because they know I will be buying product. I've seen people make tea from hops and drink it, sniff it to learn the flavors. I'd rather do this than eat the pellets. Smell everything as you brew, taste at each step when things are added and when brews are racked or sampled. Keep notes of tastings with each brew. Beer Smith has a great note section for each recipe you brew.