Depending on which source you use, the average English speaker only has a vocabulary of 2,500–5,000 words. By contrast, William Shakespeare used at least 25,000 different words in his extensive body of work.
Having a good vocabulary helps you communicate more effectively and often more succinctly. Rather than saying "someone who studies the lives and origins of living organisms," you can just use the single term, "biologist." If used without pretension, an expanded vocabulary demonstrates to others your level of intelligence. Here are some simple and fun ways to improve yours:
Read: It's cliché, but the simplest ways are often the best. Reading books that expand your mind, such as nonfiction and classic literature, expose you to all sorts of new words and concepts. Best of all, these titles tend to be free or inexpensive, as you can get them from the library or Project Gutenberg or purchase them in the clearance section of your favorite new or used bookstore. Popular fiction isn't as useful for this, but it's better than nothing.
Crossword Puzzles: I try to do at least one puzzle every day. I'm not a fan of the local newspaper, so I purchase those all-crossword puzzle books in the magazine section of my grocery. These only cost $2–3 and contain 75–100 puzzles, which I find is an excellent value for a two- or three-month supply.
Word Games: Not only can you learn new words, but you get some inexpensive social interaction at the same time. Recommended games include Scrabble, Upwords, or my personal favorite, Quiddler. If you can't find a game group, Quiddler has a solitaire version of play that is quite challenging.
Word of the Day: There are literally dozens of sites with word of the day features, and some of the larger ones have RSS feeds. Set your browser's home page to one of these sites or add their feed to your reader. I have three in my feed reader, which is probably overkill for most people, but I get somewhat obsessive about this at times. Good sites include: A.Word.A.Day, Dictionary.com Word of the Day, and TheFreeDictionary.com.
Dictionary/Thesaurus Roulette: This is the classic game of opening one of these books to a random page and reading down until you encounter a word you don't know. Read the definition or synonym list and commit it to memory. If possible, try to work it into the day's communication at least once.
If you're curious where your vocabulary level is, I've found VocabTest.com has an astounding array of tests for various levels.
