Mixing bowls come in glass, plastic, stainless steel, copper, ceramic, pottery and wood. Material may be determined by use or by personal preference.
You may prefer the lighter weight of plastic or the durability of stainless steel. Each material has its pros and cons. If you use the microwave fairly often may you may prefer plastic or glass mixing bowls. Plastic melts occasionally, however, so caution is necessary when using these in the microwave.
Most mixing bowls come in sets with several different sizes included. This allows you to choose the bowl that best fits the cooking job at hand. However, mixing bowls are also sold separately.
Mixing bowls are not usually crammed with special features, but some come with lids, which is helpful. A beginning cook should look for a set of mixing bowls that is reasonably priced and has at least four different-sized bowls.