Well astral projection or what is sometimes called out of the body experience, really is an awesome and sometimes scary experience we all have in our daily lives, rather we are sleeping or awake. You never what could happen. Mainly astral projection can be accomplish through high or deep meditation and relaxtion of the body mind and spirit. But it can also be accomplished through sleeping, which i find it is easier for me that way then mediation. But everyone is different. I would suggest start with learning your energy and meditating, working with your bodies energy is very assiental to magick and spiritualism in general. Also ground and center yourself often to help your energy balanced and not out of place. This will also help you be able to learn to be in medative state and be able to astral project from your body. But if your new and have no experience. It can take some time, such as weeks, months or even years. You just need to have patience and practice and you will succeed. But also some people might be afraid to leave there bodies because they dont know what they may encounter or know about the unknown. So sometimes it can be difficult for one to project from their psychical body. But you can learn to over come your fears with practice.
I hope this helps you out. If you need any answers or need questions just ask.
Actually very few people project while awake on a regular basis however most people will, theoretically speaking, project while sleeping.
As far as danger is concerned I would suggest you learn to "fly" or travel to higher planes. The rule of thumb is the higher you go, the more difficult to exist, thus less chance of supposed astral danger.
Meditation is often preferred for astral travel over full blown slumber because when you're totally asleep you're least likely to stay focused. You see, when you're asleep your subconscious takes over while your primary (as I'll call it for now) conscious naturally begins to rest. Intentionally projecting while sleeping requires lucid dreaming, and dream control which is extra work many don't find necessary.