And more importantly, how do I take care of this plant? This is a succulent plant, so it needs less water, right or wrong? On one site it says that I need to water it every time the top soil gets dry. I am confused as to how to take care of this plant. How do I take care of it and why the leaves are short.
Jade plant is actually Crassula, usually Crassula ovata, but there are other varieties such as Crassula rupestris; even with Crassula ovata, there are varieties with slightly smaller leaves, variegated leaves and so on, so its possible you have a slightly different variety from the basic Crassula ovata.
From the photo supplied with your other question on this plant regarding pot size, its also possible the plant is etiolated and has not had sufficient nutrients or the right conditions for the leaves to have achieved their proper size, so I'm not sure which of these is correct - its being a sub variety or just not kept in optimum conditions.
In terms of watering, these plants are prone to fungal diseases if kept too wet, but they still need water, particularly in summer, so they need good, free draining soil in a pot with good drainage. Water when the surface of the soil feels dry to the touch, water well, allow to drain freely, and water again only when the soil feels just dry to the touch. They need bright daylight but be careful about sunlight - if they're used to it already, they do very well in sun, but one that's grown without sun may burn when first exposed. More information regarding watering and general care here
I know the link refers to Crassula argentea, but that's just an alternative name for Crassula ovata, they're the same plant. Note that, although there is a recommendation for fertilizing regularly during the summer months, the plant will cope just fine with less feeding than is suggested. Recommendations regarding fertilizing are based on optimum rather than 'average' care.
This plant is not a Crassula! It is a Portulacaria afra, commonly called Spekboom or Elephant Bush in South Africa, which is where it originates. It is extremely drought tolerant, but can also grow quite fast and very lush under kinder conditions. In Adelaide, Australia (where I live) you can plant it in your garden as long as the soil drains well in the winter. In the ground the plant can easily reach 3 metres in height, but it takes pruning quite well so the size can be managed easily. It likes full sun, more sun, and more sun!
Here is a link for more information: http://www.magiminiland.org/Portulacaria.html
It is an amazing plant - one of mine is over 50 years old!