Can anyone give me a brief introduction into practicing samadhi meditation? I could start saying i understand the common principles of meditation. I had practiced a peacefull breath based meditation in the past, but i didn't have any instruction whatsoever. Recently in my life i been practicing vipassana meditation, but i ended dropping it. I think samadhi meditation may be what i'm looking for for this moment in my life.
I would recommend three great dhamma talks for you. They contain in-depth descriptions of the practice of Samatha Meditation and also how to practice it.
The first one is called "Samatha Meditation" by Ajahn Punnadhammo. In here the basic principles are discussed.
There is also a second one by him called "Samatha - Vipassana" which i would also recommend. Here he talks about the differences between the two.
The third one is called "Meditation" by Ven. Bhikkhu Bodhi. In here he talks about both Samatha and Vipassana Meditation. He discusses many aspects of the practices both basic principles and obstacles to progression.
Insight meditation is what you ultimately strive at. You can start with Samadhi and progress to insight.
When getting instructions for Samadhi meditation it is best you get this from a competent teacher who can guide you. Have a look at the World Buddhist Directory to see if you can locate some on in your area: http://www.buddhanet.info/wbd/. If you want to try out using Anapana to develop Samadhi and them progress to Vippassana perhaps you can also try out a course at: https://www.dhamma.org/en/index. (There are over 200 centres world wide.)
In case you are in the receptive area some relevant centres maybe (check if the do the type of Samatha mediation you want to practice):
You don't need much (if any at all) instruction when beginning the practise, since the aim of the practise is to concentrate the mind. The key to success in any kind of Samatha meditation is to concentrate on your meditation object for as long as you can, and keep coming back to it when your attention falls away. For example, you can use your breath as a meditation object. As you keep doing this, your mind becomes calmer and concentrated.
When you keep doing this for a long period of time (depends on how regularly you practise, how long you practise during each session, etc.), and your concentration becomes very good, then a sign of concentration appears. Here too, not much instruction is needed - you just keep concentrating on your meditation object as before, and your concentration will develop even more. As you do this, the sign of concentration becomes more and more stable. When the sign of concentration is very stable, then you switch your meditation object to the sign. The sign (if you are using the breath as an object) can be seen as a light in the inner eye, or it can be felt as a sensation at your nose tip.
But you don't have to worry about the sign in the beginning. Just keep coming back to the object, be regular in your practise and practise frequently.
If we get the sitting posture right half the work of meditation is done. His description of sitting posture is unparalleled in its precision, i.e. from my experience.