Image from The Radient Life
Meditation is the process of emptying your mind and finding calmness within, and with the modern hectic lifestyle it's often something that gets neglected. If you're reading this then you probably already have an interest in learning to meditate, but if you don't then keep reading! I truly believe there is a meditation technique for everyone, and if practised regularly it's not a choice you'll regret.
The basic premise is simple, find a comfortable position in a quiet environment where you won't be disturbed, and breathe. I alternate my technique, sometimes I prefer to count breaths up to 10, others, picture white light pouring through my body on inhales. There are a variety of different methods out there.
The point is that your mind will wander, it's natural and shouldn't be looked at as a 'failure' at all. But instead of engaging with the thoughts and experiencing floods of thoughts and emotions you should guide yourself back to your breathing (or whatever you are focussing on). It's really useful to be able to feel emotions rising from thoughts eg. 'Oh no I've got work to do' leading to anxiety and dread. And the dissociation from the thoughts can carry on into normal activities, making it easier to cope with anything that may cause unrest.
Timewise, I don't like to think about how long meditation should last. A few minutes is good for starting out, but only you will know when you feel calm. I have a 3 strikes rule, where I won't get up until the third time I think I'm ready. But you may feel uncomfortable and wish to finish immediately. The key thing is not to rush, you won't achieve calmness by wishing for it to come now now now!