There are some great samplers out there. I especially like the ones offered by 4noggins. However, another way to do a sampler is to assemble your own. This has the advantage of making you study the constituent tobaccos of the various blends, so you learn a lot before you buy anything. Right now you can get a discount on bulk tobaccos at smokingpipes.com or pipesandcigars.com. You could focus on Virginias, English blends, aromatics, or pick out a variety of different genres. I think the process of struggling with the vastness of the blends available, but limited by one retailer and bulk blends, would serve the best to learn and select. You will always have this wall of choices, so best to enjoy the process beginning now -- or at least that's one good approach. I'd order only one ounce of each blend, maybe six or eight blends, to get the best out of your shipping costs.
Don't order much of even the blends you especially like. Your tastes will develop rapidly. Save the ones you don't like as well; you may find you like them better when you try them again after a few weeks or months. Seal each in a jar and label it carefully.