The disorder may affect one or both sides of the body. How much function is lost can vary.
Symptoms may be mild at first. For instance, the patient may have a mild tremor or a slight feeling that one leg or foot is stiff and dragging.
Symptoms include:
* Automatic movements (such as blinking) slow or stop
* Constipation
* Difficulty starting or continuing movement, such as starting to walk or getting out of a chair
* Drooling
* Impaired balance and walking
* Lack of expression in the face (mask-like appearance)
* Loss of small or fine hand movements (writing may become small and difficult to read, and eating becomes harder)
* Muscle aches and pains (myalgia)
* Problems with movement
* Rigid or stiff muscles (often beginning in the legs)
* Shaking, tremors
# Tremors usually occur in the limbs at rest, or when the arm or leg is held out
# Tremors go away during movement
# Over time, tremor can be seen in the head, lips, tongue, and feet
# May be worse when tired, excited, or stressed
# Finger-thumb rubbing (pill-rolling tremor) may be present
* Shuffling gait
* Slowed movements
* Slowed, quieter speech and monotone voice
* Stooped position
Other symptoms:
* Anxiety, stress, and tension
* Confusion
* Dementia
* Depression
* Fainting
* Hallucinations
* Loss of muscle function or feeling
* Memory loss
* Oily skin (seborrhea)

Symptoms
The type and severity of symptoms experienced by a person with Parkinson’s disease vary with each individual and the stage of Parkinson’s disease. Symptoms that develop in the early stages of the disease in one person may not develop until later-or not at all-in another person.

The most common symptoms include:1

Tremor, or shaking, often in a hand, arm, or leg. Tremor caused by Parkinson’s disease occurs when the person is awake and sitting or standing still (resting tremor) and subsides when the person moves the affected body part.
Stiff muscles (rigidity) and aching muscles. One of the most common early signs of Parkinson’s disease is a reduced arm swing on one side when the person is walking that is caused by rigid muscles. Rigidity can also affect the muscles of the legs, face, neck, or other parts of the body and may cause muscles to feel tired and achy.
Slow, limited movement (bradykinesia), especially when the person tries to move from a resting position. For instance, it may be difficult to get out of a chair or turn over in bed.
Weakness of face and throat muscles. Talking and swallowing may become more difficult, and the person may choke, cough, or drool. Speech becomes softer and monotonous. Loss of movement in the muscles in the face can cause a fixed, vacant facial expression, often called the "Parkinson’s mask."
Difficulty with walking (gait disturbance) and balance (postural instability). A person with Parkinson’s disease is likely to take small steps and shuffle with his or her feet close together, bend forward slightly at the waist (stooped posture), and have trouble turning around. Balance and posture problems may result in frequent falls. However, these problems usually do not develop until later in the course of the disease.
Tremor is often the first symptom that people with Parkinson’s disease or their family members notice. Initially, the tremor may appear in just one arm or leg or only on one side of the body. The tremor also may affect the chin, lips, and tongue. As the disease progresses, the tremor may spread to both sides of the body, although in some cases the tremor remains on just one side.

The main symptoms of Parkinson’s disease are usually stiffness, shaking (tremor), and slowness of movement. Other symptoms may also develop. Symptoms typically become gradually worse over time.

Well, I guess the first reply cleared it up, but since it was pretty long, I guess Ill just send it anyway!
The symptoms of Parkinson varies a bit between different patients, even at equal stages, but a very well-defined symptom is RESTING tremor, this is different from intention tremor seen in cerebellar damage. The tremor fades with purposeful movements, as drinking a glass of water. Since Parkinson attacks the basal ganglia (Brain area dealing primary with movement planning), we will further on see problems walking, the patient will take small steps (even though he/she is able to take big ones if needed), and might easily stumble when turning around. Further on, its impossible for such patients for get up from a low chair (totally impossible), and we might also observe the so-called "rapor look", the patient does not blink (very infrequently). and does not express any facial emotions. The patient might also have problems do multiple tasks at a time, and might use a loooong time planning his/her actions.
Generally the patient is rather akinetic, he/she may move if needed (not paralyzed), but somehow they just dont "feel like moving".

symptoms of Parkinson’s disease often start on one side of your body first and then affect both sides. The main symptoms are listed below.

Shaking (muscle tremor) is usually one of the first symptoms and affects most people with Parkinson’s disease. It often starts in the hand with circular movements – as if rolling a marble or pill between your thumb and forefinger. It usually affects your arms and legs, but sometimes also your head and jaw (although this may mean you have another kind of tremor). The tremor is most obvious when you’re at rest, and is reduced when you’re moving or sleeping.
Stiffness (rigidity), which makes your limbs feel difficult to move.
Slow movement or an inability to move are common in people with Parkinson’s disease. People with Parkinson’s disease often walk with a slow shuffle.
As different muscles become affected you may develop:

problems with posture and balance – you may have falls and have difficulty turning in bed or getting out of a chair
speech changes – your speech may become quiet or rapid, making it hard for others to understand you
loss of facial expression – you may smile less, frown more and blink slowly
small handwriting
Other symptoms that you can have aren’t related to movement. These can include:

mental health problems – including depression, loss of memory, difficulty reasoning, increased anxiety and changes in behaviour
bowel and bladder problems such as constipation and the need to urinate often
problems with swallowing
weight loss
impotence
low blood pressure when you stand up
increased saliva and sweating
sleep problems and tiredness
These symptoms aren’t always due to Parkinson’s disease but if you have them, you should visit your GP.

Causes of Parkinson’s disease
The exact reasons why people develop Parkinson’s disease aren’t fully understood at present, but inherited factors seem to have a role. A family history is more common in early-onset Parkinson’s disease.

Certain chemicals in the environment that might be harmful to the brain, called neurotoxins, have been linked to Parkinson’s disease. It’s possible that people who are exposed to more of these neurotoxins are more likely to develop the condition. Doctors need to do more research on possible environmental risk factors for Parkinson’s disease.