Annie excels in teamfights with her easy-to-land, reliable stun, making her a great pick for beginners.
Annie's short skill range is a significant weakness; compensate with Phase Rush for mobility and items like Malignance, Rylai's, or Hextech Rocketbelt for engagement and utility.
Be aware of the Tibbers-Flash bug: cast Flash, then wait a slight delay before using R to avoid it deploying at your original spot. Annie has high burst potential, especially with early R + Ignite combos.