Any coin collector just starting out in this hobby should begin by getting familar with the most current coins on the market. The 2008 Proof Sets produced by the U.S. Mint are a good way to start any coin collection. Proof Sets were first introduced in 1936 and continue being produced today. 1665-1967 were the only years that an actual proof set wasn't made. The proof sets prior to 1965 tend to bring more money due to the silver content. The older proof sets pre-1950 are getting really expensive and out of the price range of most beginning collectors.
Pay particular attention to the amount of coins that were minted as well as the mint location. Many of the highest valued coins have extremely low quantities available and are from US Mints no longer in production. If ever in doubt about the coin your buying please contact the appropriate seller to answer any questions. Keep in mind that condition is of upmost importance when creating your coin collection