Yoga is not a competitive sport. You can not win points for matching a picture in a book. Pressing too, is probably not to your liking, and you can do damage. Whenever possible, work with a teacher, and the use of books, videos and websites to supplement their classroom instruction. Above all, stick with it. If you practice, you will improve. And you will feel better.
Below are the yoga techniques you need to know, try to get some practice in a relaxed manner.
Sit/Easy Position
A starting position that helps focus awareness on breathing and the body; helps strengthen lower back and open the groin and hips.
Sit cross-legged with hands on knees. Focus on your breath. Keep your spine straight and push the sit bones down into the floor. Allow the knees to gently lower. If the knees rise above your hips, sit on a cushion or block. This will help support your back and hips. Take 5-10 slow, deep breaths. On the next inhale, raise your arms over your head. Exhale and bring your arms down slowly. Repeat 5-7 times.
Increases flexibility of spine
This is really two poses, one flowing into the other. Begin on your hands and knees. Keep your hands just in front of your shoulders, your legs about hip width apart. As you inhale, tilt the tailbone and pelvis up, and let the spine curve downward, dropping the stomach low, and lift your head up. Stretch gently. As you exhale, move into cat by reversing the spinal bend, tilting the pelvis down, drawing the spine up and pulling the chest and stomach in. Repeat several times, flowing smoothly from dog into cat, and cat back into dog.
Read more: http://www.yogasite.com/postures.html