Most bedrooms for children tend to be small, so size will certainly be a primary concern when choosing a kids' bed frame. When considering size, it is also important to think about the size of the child, not only now, but also as he or she grows. Infants will of course need a crib or other enclosed bed, but for growing children, a twin size mattress might be most appropriate because it is not so large that the kids' bed frame will take up a significant amount of space in the room, but also not so small that the child will not have room to grow.
The kids' bed frame itself can be made from a variety of materials and come in any number of styles. Some frames will be made from lower end materials such as particle board in order to keep the cost of the unit down. A particle board kids' bed frame is a good choice if you are on a budget and expect to replace the frame in a few years. Remember that kids can be tough on furniture, and particle board is not exceptionally durable. If you are willing to spend a bit more, consider softwoods; hardwoods are the best choice because they are exceptionally durable and beautiful, but they will also be the most expensive option.
Many kids' bed frame models are made from plastic, and such frames may even be shaped in various ways that will appeal to kids. Some frames, for example, are shaped like race cars, and others may be shaped like a castle. These are fun options that will certainly help make the bedroom one of the child's favorite rooms in the house, though they, too, can be more expensive than other options and the child is likely to outgrow this type of bed as his or her tastes develop.
Another great option for a kids' bed frame that is also fun for the child and space-saving for the room in general is a loft bed. Such beds are raised high off the ground, much like a bunk bed, and while the loft bed may feature a low bed in the same style as a bunk bed, it may also have a desk in the lower bed's place, or simply an empty space used for storage of toys, drawers, or other items commonly found in a child's room. The top bunk is accessible by a ladder, and the frame itself can have built-in storage features as well.