Professional investors spend years honing their skills to find great investments. But even if you don't want to dedicate your entire life to the pursuit of stocks that will make you rich beyond your wildest dreams, you can still be a successful investor -- with the help of some simple tools.

All about ETFs
This week, I'm taking a look at some of the most versatile investment innovations of the past 20 years: exchange-traded funds. Beginning with the SPDR Trust in 1993, ETFs have blossomed into a huge industry, with more than $530 billion invested as of the end of 2008, according to the Investment Company Institute.

In particular, a huge part of the ETF universe focuses on large-cap U.S. stocks. Given how important a role these stocks play in the portfolios of most U.S. investors, making the right investments can make a huge difference to your overall performance.

Starting with the basics
Any look at large caps has to start with SPDRs. As index-tracking ETFs that are designed to mimic the S&P 500, SPDRs give you exposure to top-name stocks like ExxonMobil, Microsoft, and AT&T, along with the rest of the 500 stocks in its benchmark index.

Beginning investors who are satisfied with the prospect of matching the S&P's returns often look no further than SPDRs. But there are several other ETFs with different focuses that are also worth a closer look.

Losing weight
One thing about SPDRs that some investors have trouble with is that the S&P 500 is weighted by market capitalization. That means that ExxonMobil makes up more than 3.5% of the index, whereas smaller large caps like Nasdaq OMX Group (NASDAQ:NDAQ) and Whole Foods (NASDAQ:WFMI) have relatively little bearing on the value of the index as a whole.

If you'd prefer to own an equal amount of all of the large-cap stocks included in the S&P 500, the Rydex S&P Equal Weight ETF (RSP) fits the bill. This ETF simply maintains equal-sized positions in each of the S&P's component stocks. It rebalances only once every quarter, so imbalances may arise. For instance, Advanced Micro Devices (NYSE:AMD) and (NASDAQ:AMZN) are currently overweight in the portfolio.

Overall, though, the weighting is far more even than a standard S&P fund. And over the past five years, the strategy has beaten SPDRs by more than a full percentage point in average annual return.

Drilling down
If you're not looking to own a piece of every large-cap stock out there, you can slice and dice the large-cap space nearly any way you want using ETFs. Take the following examples:

  • The iShares S&P 500 Value ETF (IVE) focuses on stocks that S&P defines as value stocks, which currently include General Electric (NYSE:GE), AT&T, and JPMorgan Chase (NYSE:JPM). Its shares have lagged the overall market over the past five years, but if you think value stocks are poised to keep rebounding, then shares may represent a bargain.
  • If you'd prefer to focus on large-cap stocks that pay dividends, a dividend ETF such as the Vanguard Dividend Appreciation ETF (VIG) could help point you in the right direction. In a tough market environment, the ETF has lost money over the past three years. However, it has performed relatively well compared to the broader market, despite having badly lagging, dividend-cutting financial Wells Fargo (NYSE:WFC) as its top holding.
  • ETFs open the door to just about any sector-specific investment play you want to make. From technology to utilities, health care to industrials, sector ETFs let you tailor your portfolio to emphasize whatever part of the market you want.

Best of all, investing in ETFs is as easy as opening a brokerage account and buying shares. With the ability to buy and sell shares anytime the market is open, it's easy and convenient to get started.

Invest today
So even if you don't have the time to research individual stocks the way you'd like, don't miss out on the profits that successful investors earn. With ETFs, you can make money with large-cap stocks simply and easily.

Stay tuned all this week to Dan's "Simple Ways to Win" series. Up tomorrow: small caps.

Fool contributor Dan Caplinger likes to keep everything simple. He owns shares of General Electric and SPDRs. and Whole Foods are Motley Fool Stock Advisor picks. Microsoft and Nasdaq OMX Group are Motley Fool Inside Value recommendations. The Fool has written puts on Nasdaq OMX Group. Motley Fool Options has recommended a diagonal call on Microsoft and writing puts on Nasdaq OMX Group. Try any of our Foolish newsletters today, free for 30 days. It doesn't get simpler than The Fool's disclosure policy.