Many say buy a package of drug store/over-the-counter (OTC) tobacco and light up. That's what I did (my dad owned a general store) but I don't recommend it.
I suggest you go to a decent tobacconist and, hopefully, the tobacconist will be able to recommend a few bulk blends for you to try. Bulk blends are usually quality tobacco in various types (English, Cavendish, Virginia, Aromatics, etc.) that you can buy small amounts of (they are sold by the ounce). Be sure to talk it up with him first so your tobacconist can get a feeling of what you might enjoy. Aromatics (like Lane's 1Q) are usually the first recommendation for n00bies, but see if you can try an ounce of a few types of tobaccos. Bulk blends usually sell for $2-$5 an ounce and many also come in tins.
Once you narrow down the types you like after sampling these (and maybe some others) you will, over time, find types of blends and brands you really enjoy.
If you live in East Bumf*ck (like me) and there isn't a tobacconist reasonably close to where you live, try calling one of the better on-line vendors toll-free (like Bobby at
PipesandCigars.com, or Richard at
4noggins.com who will be happy to talk you through the process and provide you with some recommendations.
To get you started, here's a few bulk blends you might enjoy: Lane 1Q (aromatic), Mac Baren's 7 Seas Regular (aromatic), Peter Stokkebye Bulk Luxury Bullseye Flake (Virginia/Perique/Black Cavendish cut in coins, non-aromatic), Samuel Gawith Best Brown Flake (Virginia, non-aromatic), Hearth and Home Ambassador's Blend (English, non-aromatic).
Good luck and let us know how you made out!