I would recommend reading- 'Astral Projection for beginners' by Edain McCoy, 'Treatise On Astral Projection' by Robert Bruce, which you can download free on a site called, Occult underground. Also Brad stieger's 'Mastering the art of astral projection'CD, which you can buy from the SoM online store and also '74 minute course of astral projection CD' by Dick Sutphen, I got this from ebay.
I also found Silver Vixen's video on astral projection which is on this site very helpful.
When trying astral projection I recommend practising getting into a relaxed enough state or a trance like meditative state. You need to be very relaxed to be able to do project.
Chakra stimulation helps and also erasing any fears you may have of astral projection, I've heard a lot of people fear not being able to come back, but its natrual and automatic that you can always return to your body. Some people fear possible attack on the astral plane, but It is very, very easy to defend yourself if need be, or to get away, as, there is both positive and negative on the astral planes, like on this physical plane.
Be very patient with yourself as Rome wasn't built in a day, regular practise and again meditation and chakra stimulation are very valuable in this and in other areas of magick