Continue to learn as much as you can about physician-specific personal finance through the abundance of books and blogs available on the Web (i.e. The White Coat Investor Network).
Plan to save as much as you can (aiming for 20% of your gross income) starting in residency and increase this as tolerated to a maximum comfortable value.
Generally, a higher percentage of stocks will be needed to meet investment goals faster if your investment time horizon is shorter
Consider a portfolio of low-cost index funds (or even just one S&P 500 Fund or Total Stock Market Fund).
Another excellent option for a balanced, more diversified portfolio includes 30% Total Stock Market Index Fund, 30% Total International Stock Market Index Fund, 10% REIT Index Fund, 30% Total Bond Market Index Fund.
Fund this portfolio with consistent (i.e. monthly) investments to take advantage of dollar cost averaging.
Plan to hold these investments while resisting the urge to time the market (Buy and Hold).
Rebalance your portfolio annually to reflect these percentages based on losses and gains in your various funds.