If this pose looks pretty simple to you, then your eyes deceive you. Although it may seem like this pose is one that lets you relax on your knees, it actually requires much flexibility from the ankles, thighs and hip flexors. You are indeed a hero if you can master this pose delicately without feeling pain eventually, but not all warriors feel pain. As its name indicates, vira, meaning ‘hero’ and sana, meaning posture, the hero pose will lead you to become a conqueror of your own mind, bring to it a sense of peace and tranquility, and master the conflicts in your mind. When you are in this pose, it is important to elongate not only your spine but also your neck, your chin and your sense of understanding with both yourself and the world. Now relax and take a deep breath as you envision yourself freeing your mind from desire.
This pose stimulates Vajra Nadi, activates prana in Shushumna and redirects sexual energy for spiritual purposes. Vajra Nadi is located within Sushumna.
Not recommended to perform right after prolonged kneeling poses. The best preceding poses would be standing such as Vrksasana (Tree pose), Trikonasana (Triangle pose) and any variation of Virabhadrasana (Varrior poses).
The best pose to get right after is Adho Mukha Svanasana (Downward facing dog pose) or Prasarita Padotanasana (Standing forward bend pose)
Sources:
http://www.yogajournal.com/basics/2339
http://www.drweil.com/drw/u/ART03448/Hero-Pose.html
Asana Pranayama Mudra Bandha by Swami Satyananda Saraswati
sequencing is as per dowsing