Here's how to use Morningstar’s free Fund Selector to find stock index funds with low expenses, low startup requirements, and automatic investment plans.

Especially if you're just starting out, on the first screen you might want to accept each of the default settings except five. You're pretty much assured of finding some decent index funds if you use these settings:

Fund group = Domestic Stock.

Minimum initial purchase less than or equal to = $500.

Load funds = No-load funds only.

Expense ratio less than = 0.50%.

Turnover less than = 75%.

Click on "Show Results." The resulting short list will include both index funds  other types of funds.

For a profile of the fund, click on its name. When you find an index fund that might work for you, click on "Purchase Info" under "Nuts & Bolts" to find the fund's phone number and whether it has an automatic investment plan, or AIP.

(Do you need the psychological comfort of signing up with a winner, even though there’s no evidence that a fund with high returns in the past has a better-than-average chance of excelling in the future? If so, consider first the index funds that have relatively high Category Ratings (maximum is 5) and Morningstar Ratings (maximum is 5 stars).

You can also click on "Trailing Returns" under "Total Returns" to get a rough sense of the fund's historical performance. For more detailed historical comparisons, you'd have to sign up for Morningstar's paid membership. Or you can simply note the fund's ticker symbol and then switch over to Yahoo! Finance to get a good deal of historical information for free.)

If this screening method seems too complicated, there’s a simpler method:  simply buy shares of a large, established index fund, such as those offered by Vanguard or TIAA-CREF.