Like cedar, redwood is used mostly for outdoor projects because of its resistance to moisture. Redwood (California redwood) is fairly soft and has a straight grain. As its name suggests, it has a reddish tint to it. Redwood is easy to work with, is relatively soft (2 on a scale of 1 to 4), and is moderately priced. You can find redwood at your local home center.
Even if you are using a beautiful (yet unstable) grain pattern on part of your furniture, it’s a good idea to use stable wood on the other parts. For example, look at an old wooden door. The panels usually have more decorative (less stable) wood, but the rails and stiles (parts of the frame) are usually very stable straight grained wood (don’t worry, I’ll clarify “straight grain” below).