If you are looking for wooden furniture, you should look at more than just the outside. You have to also check out the guts of the piece - behind doors, inside drawers. In a lot of cases, visually inspecting something will allow you to figure out how durable the furniture piece really is. This will help you determine the age and quality of the piece.
A solid well-made frame is essential to a good and comfortable sofa. Look for thick wood and avoid pieces that are made with thin or fragile pieces. You will have a squeaky couch if the board is thinner. Try out the sofa, changing positions on it. If the frame is not sturdy, it will creak.
Consider your wall colors and flooring and bring samples of it if you want your furniture to go with it. In the store you may fall in love with the item, but once you're home, it can be an entirely different story. Avoid this at all costs. You can do this by taking a photo of the room the new piece will be placed in, or by using a color swatch to see if it matches.