If you haven't given your portfolio a checkup since the stock rally began in March, now is a good time to make sure you've got the right stake in equities. But if long-term growth is your goal, advisers say you should never make decisions based on temporary market conditions.

"Earlier this year, when the market was looking so bleak, a lot of people bailed out of stocks, and that was a mistake," said Eric Tyson, a former financial counselor and author of the guidebook "Investing for Dummies."

"I am always banging the drum, saying, 'Guys, you buy stocks when everyone else doesn't want them, when they're cheap!' And now they're not so cheap anymore."

If you're not certain how to allocate your money, many fund companies and retirement-plan sponsors have online questionnaires to help.

"I know sometimes people are influenced by something they hear on TV or from a friend or in the company cafeteria, but it's not wise to make decisions based on things like that," said Diane Maloney, president of Beacon Financial Planning Services in Plainfield, Ill. "We are all unique, and we need to make decisions based on our own circumstances."

The stock portion of your holdings should include a diverse mix of small-, mid- and large-cap companies, and domestic and international stocks. For example, a fairly young investor would want to have 15 percent to 20 percent allocated in mid- and small-cap funds, Maloney said.

Once you determine the proper mix, you can take a closer look at your investments. For those who rely on mutual funds, the first of the year is an appropriate time to do this, because funds will be reporting their year-end results.

It's important for tax reasons that you make changes to your holdings after Jan. 1. If you do it before then, you risk having to pay capital gains taxes on distributions a fund made earlier in the year, before you owned shares. This isn't a factor with retirement accounts, as taxes are deferred on those investments until you withdraw them.

"A fund that might not do well one year is not necessarily one to trash, but one that hasn't done well for three to four years, that might be a sign you should find something better for yourself," Maloney said.

One way to see how your fund has performed against the various market indexes is to look on www.ishare.com. Looking over a fund's prospectus is also a good way to get a picture of its performance and recent history, though many investors skip this step.

"I'm always surprised at how people will waste their energy," Tyson said. "They'll flick on CNBC four times a week to see the price of something, but they won't read their fund's annual report when it comes in the mail."

Although the mutual fund industry has gotten some negative publicity lately, it's still the best investment for most people, Tyson said — as long as you choose your fund family carefully.

"You have a day job, whether you're a nurse or a janitor or whatever, but whatever it is you do for a living, it ain't managing money," Tyson said.