Finding the discipline and wherewithal to save for retirement is tough, but it’s especially hard for people with modest means and little investing experience.

That made an H&R Block product called Express IRA easy to sell. People who went to the tax-preparation company’s offices for help with their returns could set up these retirement accounts at the same time, often using tax refunds for their deposits.

Block calls the accounts a success, helping more than half a million people start saving.

But New York Atty. Gen. Eliot Spitzer recently sued the company for $250 million, accusing it of “fraudulent marketing” and claiming that 85 percent of the customers paid Block more in fees than they earned in these low-interest money market accounts.

Block denied any wrongdoing. But regardless of whether the company broke any laws, its Express IRA is a textbook case of how not to invest for retirement. People with small amounts to invest have many better options, and I’ll mention a few below.

The first red flag: Beware any investment advice from someone who’s not an investing expert – a tax preparer, for instance.

Next, be skeptical about any adviser who steers you to his firm’s products.

Finally, when it comes to retirement investing, remember that being overly conservative actually means bearing a lot of risk – the risk that your investments won’t grow enough.

A few funds offer starting minimums of only $250 for IRAs, and you can find them using the fund-searching tool offered by Morningstar Inc. at its site, www.morningstar.com. But look carefully at the annual fees called “expense ratios,” which are often higher for low-minimum funds.

An alternative is offered by ShareBuilder Corp., an online brokerage at www.sharebuilder.com that has no minimum requirement for opening an account and charges only $4 to trade any of thousands of stocks and funds.

There is an annual account fee of $25 for IRAs, which could be quite damaging to a small account – 10 percent of a $250 account, for instance. So don’t open an account until you had saved $500 or $1,000. To minimize the damage from the $4 trading fee, make subsequent contributions no smaller than $200.

Choosing the best investment is too big a topic for today. But as a starting point take a look at the Standard & Poor’s 500 exchange-traded fund with the ticker symbol IVV. With this, you could match the performance of the broad stock market, which has averaged about 10 percent a year over long periods. And the annual expense ratio is an infinitesimal 0.09 percent.