Each Assan has its own benefits & process, before starting yogassan one should consider about his / her health first, if he / she is not enough healthy than do not start with some tough assans. One more point we must keep in our mind is do the yogassan according to our body strength.
Some common rules regarding yogassan before you start it :
* Do the yogassan in early morning time after you get fresh.
* Yogassan must be done in open space so that you will benefit of fresh air.
* Take the rest in between assan(s).by doing Shavassan.
* Start with simple assans first & later on when you will get use to of doing them go to the advanced level.
* Yogassans may be done at evening time also but after 4-6 hrs. of taking meal.
Here are some of important assans I'm mentioning to you these are Padmasana, Vajra asana, Sarwangasana, Bhujang asana, Yogamudra asana, Hala asana, Makarasana, Shalabhasana.
- Padmasana

depicting the holy sign, as in Chin or Jnana Mudra.
Benefits of Padmasana :
Padmasana destroys all disease and awakens kundalini energy (one’s dormant spiritual energy). It calms the mind. It stimulates the pelvis, spine, abdomen, and bladder and stretches the ankles and knees
2. Vajra Asana

legs towards the back and both toes should touch each other. Keep the
heels apart and let buttocks rest on heels, or let them lie in between the heels.
The waist neck and spine should be in a straight line. Rest both your hands on the knees and keep the elbows straight. Look towards front, breathe normally.
Benefits of Vajra Asana :
Those having gas problems should perform this asana, immediately after a meal. It provides relief from sciatic pain. The benefit of Vajrasana done for 5-7 minutes is equivalent to a long walking exercise. Also, the diamond pose (Vajrasana) is very beneficial in curing the problem of varicose veins.
3. Sarwangasana
First lie flat on your back. Inhale deeply while raising your legs and spine until the toes point to the ceiling.
The body rests on the shoulders and the back of the neck. The body is supported by the hands, which are placed on the center of the spine between the waist and the shoulder blades. Keep your spine and legs straight.

about two minutes.
To come out of this posture, just bend your knees, curve your back and slowly return to lying on the floor while exhaling. First bend your knees, put the palms on the floor, then curving the spine, gradually unfold it the way one unrolls a carpet. When your entire back touches the floor, straighten the knees, take a deep breath and slowly lower your legs to the ground while breathing out.
If you wish, you may go straight into the next posture (the 'reverse posture') instead of lying down.
Benefits of Sarwangasana :
It provides relief from certain conditions, such as asthma, shortness of breath and heavy breathing. AS we know "Junk foods and other Fast foods" result in digestive problems. Better digestion improves the overall health of the individual. Improvement in diet and shoulder stand relieves anemia and related conditions. If Sarwangasana is done in the early hours of the morning, it relieves fatigue associated with little or excess sleep. It also helps to treat back related problems and back ache.
4. Bhujang Asana

Benefits of Bhujang Asana :
It strenghtens the spine, stretches chest & lungs, shoulders. Stimulates abdominal organs. It also improves digestion system. According to HathYoga Bhujangasana increases body heat, destroies many diseases & also awakes Kundalini power.