The most popular deciduous bonsai trees are maples, elms, ginkgos and apricot trees. 
The standard Chinese elm can reach sixty feet.  Indoor bonsai may keep their leaves, but should be taken out it the cold where they will behave in normal deciduous form, losing their leaves. These are easy for beginners because the growth is predictable and is forgiving of pruning errors. 
Maples also make good beginning bonsai as they are sturdy, forgiving and the changing leave colors are fascinating.  The most common maples bonsais are Japanese maple and trident maple. 
A Japanese native, the ginkgo tree bears a healthful fruit.  Leaves are fan shaped and turn yellow in the fall.  Ginkgos can live 100 years but grow only 16 inches tall. 
The Apricot bonsai is from China where both the fruit and flowers are of value.  These plants only live for 9 years and grow 17 inches tall.  Flowers begin in early spring with the fruit following in the summer.

Deciduous bonsais should be outside during the spring, summer and fall seasons with ample sunlight.  Deciduous bonsais can be brought inside for only a few days.  During the winter they should be stored in cold, dark places (even buried) so that dormancy can be achieved.

As mentioned above, in the winter deciduous bonsai should be stored in the dark and where temperatures are cold. 

Deciduous bonsai should be watered when the soil is dry and the soil should remain moist.  Trees in direct sunlight, should be watered daily.  Water until the water runs out of the pot.  When in dormancy, water only every two weeks.

Deciduous bonsai trees are generally safe for humans and pets.   Exceptions include Apricot which is moderately toxic and Chinese Elm and maple which are mildly toxic.

In addition to juniper, cedar, pine and cypress, there are also hemlock, blue spruce and Scott’s pine.

Evergreens generally need full sun, however, some grow well in the shade.

Coniferous evergreen trees are cold tolerant, living in the coldest regions of the planet, however, rainforest evergreens such as mahogany, ironwood, and tamarind prefer warmer temperatures.

In general, evergreen bonsai trees need lots of water.  Coniferous evergreens like dry, well-draining soils, however rainforest evergreens prefer moist, soggy soils.  Don’t overwater—this can lead to root rot.  Water when the soil is dry. We place a wooden chopstick in the soil for a few minutes and check for moisture. If it’s dry, it’s time to water.

Evergreen bonsai are generally non-toxic to pets.   Juniper is mildly toxic.  (A Hemlock tree is not the same as “poison hemlock,” which is a plant resembling Queen Anne’s Lace.)