Spring and summer are historically the biggest times of the year for buying and selling homes. At the same time, because of the economy, if you’re in the market to buy or sell, you need a little help.

The first step to a successful purchase or sale is to learn as much as you can.

Two online real-estate sites, Zillow and Trulia, are good places to get not only baseline information, but to learn tricks of the trade.

Some features of Zillow [www.zillow.com]:

“Zestimate” — a property’s valuation based on comparables and database information, which you need to know whether you’re buying or selling. The value can come in handy when comparing to an appraisal or a market analysis by a real-estate agent.

Inventory — Whether there are more or less properties in your area available for sale impacts you as a buyer or a seller. More properties on the market make it easier for buyers to negotiate a price, but forces sellers to price more competitively.

Make Me Move — Potential buyers can make an offer via email.

Listing — Promote your property for free for 60 days either by yourself or through an agent.

Rental — Zillow can help determine the correct rental price for your property if you decide not to sell.

Some features of Trulia [www.trulia.com]:

—Search for homes by price, features and open houses — Get smartphone alerts when there is activity on properties you’re interested in.

—Review school ratings, crime and business comments from those who live locally or participate in the Q&A forum.

—Read articles by real-estate experts on topics ranging from avoiding surprises in the buying process, to how to making springtime changes to attract buyers.

Whether you’re buying or selling this year, schedule an information-only talk with a local real-estate agent. Seek professional advice in advance of taking any steps toward buying or selling.

If you’re a buyer: Check your credit scores. Send for your credit reports and review them for any errors. Get pre-qualified so you know your price range.

If you’re a seller: Make all small repairs, and do a bit of landscaping. Get multiple opinions about whether the cost of a more major project (updated kitchen or baths) will likely be recouped in your sales price.

In short, gather all the information you can before you move forward.

David Uffington regrets that he cannot personally answer reader questions, but will incorporate them into his column whenever possible. Write to him in care of King Features Weekly Service, P.O. Box 536475, Orlando, FL 32853-6475, or send e-mail to columnreply@gmail.com.

(c) 2012 King Features Synd., Inc.