Mutual funds are not guaranteed or insured by the FDIC or any other government agency even if you buy through a bank and the fund carries the bank's name. You can lose money investing in mutual funds.
Past performance is not a reliable indicator of future performance. So don't be dazzled by last year's high returns. But past performance can help you assess a fund's volatility over time.
All mutual funds have costs that lower your investment returns. Shop around, and use the SEC's Mutual Fund Cost Calculator at www.sec.gov/investor/tools.shtml to compare many of the costs of owning different funds before you buy.