Blizzard announced the Welcome Bundle, a Hearthstone deal that nets you over 50 cards for only $4.99.
To be included in the game's next update, the Welcome Bundle consists of 10 Classic card packs plus one Legendary card from the Classic set. Each Classic pack contains five cards. "If you’re new to Hearthstone and wondering where to begin, the Welcome Bundle will set you well on your way to building a Classic deck recipe or creating an exciting new deck of your own. You’ll unwrap one of nine Classic class Legendaries, such as the mystical Mage card Archmage Antonidas, or the relentless Warrior card Grommash Hellscream."
Keep in mind that the Welcome Bundle is available only once per Hearthstone account.
After building Classic decks, new and returning players will have a lot of fun to catch up on, including Adventure modules like One Night in Karazhan.