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Is your mattress destined for the dumpster? You definitely need to buy a new bed if yours is more than nine years old, if you wake up feeling like you haven't even slept (and it's been nine hours!), if the surface is covered with bumps and lumps, or if you need to be pried from the sinking sag in the middle. Even if your bed is a dream, it's worth checking out the latest offerings for the newest mattress features.

Step 1: Obviously, your space will determine how big a bed you can buy. Be on the lookout for manufacturer-specific sizes -- some companies now offer a slightly larger queen size marketed as a "European Queen." Arm yourself with a tape measure and jot down the exact size of the mattress, then compare it with standard bed dimensions.

Step 2: Comparison-shopping can be tricky when it comes to mattresses; models vary tremendously between retail stores. Your best smart-shopping strategy is to find a sleep set that feels just right, then shop around for similar comfort and support levels. Expect to drop $1,000 for a reputable queen-size mattress with a box spring -- essential to prolonging the life of your bed. Top-of-the line British VI-Spring Company handmade mattresses can reach a whopping $20,000.

Step 3: "When it comes to sleeping surfaces, what might feel wonderful to one person might feel like a concrete floor to someone else," says Nancy Blatt, executive director of The Better Sleep Council. In order to find the perfect fit, grab your mate and head to a trustworthy mattress store. You'll both need to lie down in your favorite sleeping positions and try out mattress comfort levels, from plush to firm. But don't let a cashmere covering sweep you off your feet. Pay special attention to how the mattress supports your shoulders, hips, and lower back -- too little support can lead to back pain and too much can add unnecessary pressure.

Step 4: Next, look inside the box. It's the quality of the materials used and how they're put together that determine how long a mattress and foundation will provide comfort and support. The best mattresses have more springs that are intricately arranged and hand-tied with loving precision. But delicate craftsmanship is going to cost you. Bottom line: Look for details like a complex coil shape (it'll provide better weight distribution) and a thicker wire diameter (for greater resiliency). Each spring system suggests a different feel, so let your body be the judge. Sweet dreams.

Mattress Size Chart
California King: 72" x 84"
King: 76" x 80"
Queen: 60" x 80"
Full ("double"): 53" x 75"
Twin: 38" x 75"

(All dimensions may vary by +/- one-half inch)
From: The Better Sleep Council

You Want
A Firm, Traditional Mattress
Invest In: An Innerspring Mattress
What Is It: Inside are springs -- tempered steel coils -- and layers of upholstery on either side to cushion you. Some come with cushy “pillow tops” for a thin layer of comfy fluff. They come attached (it’s almost like having a comforter that’s sewn to your mattress) or can be purchased separately. You’ll probably need to buy fitted sheets marked “deep”. The pillow top can potentially add several inches to your mattress’ depth and a normal-sized fitted sheet may slip off.

You Want
A Mattress that Cradles Your Body
Invest In: A Foam Mattress
What Is It: This isn't the flimsy foam you'd find on a college dorm bed. New deluxe styles are made of solid foam, sometimes in just one piece -- or a multilayer combo. Tempur-Pedic is a popular brand that uses viscoelastic foam.

You Want
You Like Your Mattress Soft, He Likes It Firm
Invest In: An Air Bed
What Is It: They look like innersprings, but are actually filled with air instead of springs, and are often adjustable (one of the most well-known brands is Select Comfort’s Sleep Number Bed [FC: The Sleep Number Bed made by Select Comfort] , which is an airbed that’s core has been divided in two, allowing each side of the bed to be adjusted separately).

You Want
Your Current Mattress Is Fine, But It Could Be Comfier
Invest In: Memory Foam
What Is It: This cushy foam sits on top of your mattress. Developed by NASA in the '70s to provide comfort to astronauts during takeoff and landing, it molds to your body depending on your temperature (the more heat you emit, the softer is becomes).

Now learn about how to choose the right comforter.

-- Kathleen Murray

See More: Buying Furniture