As career choices go, drinking wine and talking about it sounds like pretty pleasant duty. That's a short version of what a sommelier does, but like most simplifications it leaves out a lot of the less-glamorous details. There are several career paths open to sommeliers, but long hours and unexciting administrative work are usually a part of the job description.
Restaurants
High-end restaurants are a major employer of sommeliers. The sommelier works with the chef and the restaurant's owners to maintain a suitable variety and quantity of wines on hand, to complement the chef's food and provide a more complete experience for the diners. Physically managing the inventory is a major part of the job, from ordering and receiving bottles to ensuring they're stored appropriately.
During service periods the sommelier visits diners at their tables, recommending wines that complement the food yet also respect each diner's personal preferences and level of sophistication. An ability to explain a wine's character without the use of industry jargon is especially useful.