Meditation is really a spontanious state, but practicing meditation is what I think you refer too.
With regards to learning meditation. There are many techniques, and various stages in most of the techniques. Some are best learned before others. Some pranayama techniques can be used as meditation. In fact the ashtanaga vinyasa yoga system combines asana, bhanda, pranayama into one flowing practice that is a meditation in motion, and it is AMAZing once you become famialiar with it.
However one thing I know from personal experience is that learning from a good teacher is invaluable. Books might give you the technique, but timings, attitude and other less tangiable aspects do not come accross from books. It is these less tangiable aspects that are vital in gaining a good start and appreciation to the art of practicing meditational techniques.
Also, being guided to start with really helps with the memory and getting the vibe/rythm of practice. Also getting the sitting position right can take years of yoga practice alone.
However, if no teachers are readily available, then a good book to start with might be Meditation from the Tantras (Bihar School of Yoga Publications). This is one of the key texts we use on my yoga teacher training course.
The key tip with meditation (assuming it's a seated meditation) is to become comfortable in a seated posture, allow the body and mind to become still. And then to start working with the chosen technique. Meditation relies upon (amongst other things) concentration and awareness.
I suggest trying 5-10 minutes to start with and becoming comfortable with that, no need to rush lengthending the practice.
Antar Mouna is a good practice, especially stage 1 for a beginner or some one who wants to start again.
The other thing I wanted to say was, if you can practice a bit of asana, some pranayama and then sit for meditation you will find it more beneficial.