My wife and I have $1,000 a month available to invest for our retirement and our children’s college educations. Can you suggest some safe investments for these? Should we restructure our budget to have, say, one car instead of two? What percentage of our income should go toward investing?

Wow! That’s a lot to cover. But it’s worth a try, as this is a very typical set of concerns.

There’s no hard and fast rule on what percentage of your income should go toward investing.

The younger you are, the less you need to invest to meet a given goal, as you have more time for your investments to grow. The amount you need to invest also depends on the other assets you expect to have in the future. If you have a generous pension plan, you don’t need to invest as much for retirement, for instance.

Look at budget

I’d start the planning process with the household budget. Keep records for several months of everything you spend — and I mean everything.

Then look for painless cutbacks. Maybe you’ve got one more tier of cable service than you use, and there’s a good chance you can save by shopping for cheaper cell phone, long distance and Internet service. There might be savings in homeowner and car insurance as well, especially if you’re willing to agree to higher deductibles.

I’d look at the big-ticket items, too — whether to cut back to one car or to find a cheaper place to live.

But before taking such drastic steps, do some careful calculations to see if they’re necessary. If you have a computer, get a copy of Quicken 2004, the financial program that has sophisticated retirement and college savings calculators. You’ll find it in any computer store or online at www.quicken.com.

If you don’t have a computer, go to a library that has one and try an online planning software at the site run by one of the big mutual funds: www.troweprice.com, www.vanguard.com or www.fidelity.com.

Most people don’t have $1,000 a month available for investments, so you’re starting in a relatively good position. And you could make it even better by finding budget cuts to stretch the figure.

Where to invest

You said you want “safe” investments. But remember that the safer the investment, the slower it will grow. This year, for example, you’d be lucky to get 1 percent interest in bank savings, though your principal would be very safe.

Meanwhile, the average big-company stock, measured by the Standard & Poor’s 500 index, has returned about 23 percent since the start of the year, though there’s a greater risk of future loss than with bank savings.

Your investment decisions will be affected by the amount of time you have until you need your money. If that time horizon is 10 years or longer, you may well want to put most of your money into stocks or stock mutual funds, since you’ll have time to wait out any market downturns.

With a shorter horizon, more of your money should be kept safe in bank savings or bond funds.

For college savings, consider a Section 529 plan or a Coverdell plan. With both, investment gains are tax-free so long as they’re used for college tuition and other qualified expenses. There’s lots of good information at www.collegesavings.org and www.savingforcollege.com. Or get the book “The Best Way to Save for College” by Joseph Hurley.

Watch fees

With all investments, keep a couple of things in mind: First, pay as little as possible in sales commissions and other fees, as even small fees chew deeply into long-term results. If a 1 percentage point fee reduced your average annual returns from 8 percent to 7 percent for 20 years, a $1,000-per month investment would grow to $521,000 instead of $589,000.

Also look for investments that won’t trigger a lot of annual taxes, as these, too, undermine compounding. Tax-efficient investments such as 401(k)s and Individual Retirement Accounts work well. Index-style mutual funds and funds specifically designed to minimize taxes are another good alternative.

For most investments, I’d choose mutual funds, since they offer professional management and diversify, or spread, your money among many stocks or bonds, so you won’t have too many eggs in one basket.

You can research funds at the site of Morningstar Inc., the fund-tracking compaorningstar.com. Or get the book, “Morningstar Funds 500.”

Professional help

With such critical decisions to be made, you may want professional help. I prefer fee-only financial planners, who charge a set amount or hourly fee to help clients build long-term plans. The planner, thus, has no financial incentive to steer you to certain investments or to get you to do lots of trading to rack up sales commissions.

Though you may spend several thousand dollars on an initial plan, it should only need updates every year or two — and they will be much cheaper. The plan should be specific enough so you can make the investments on your own directly with a fund company or through a deep-discount broker.

You can find a fee-only planner by contacting the National Association of Personal Financial Advisors at www.napfa.org or calling (800) 366-2732.

The larger Financial Planning Assn., which includes advisers with a variety of compensation approaches, also has a referral service, at www.fpanet.org/plannersearch/plannersearch.cfm. Or call (800) 282-7526.

A warning: “Fee-only” also refers to planners who will manage your investments for you. They charge a fee based on a percentage of the value of your accounts, typically starting around 1 percent a year.

I’m very leery of this approach because it means paying a fee year after year even on investments that are left unchanged. As we saw above, a percentage point or two can have a drastic effect.