The first time I did shrooms was about a Half 1/8th, and they were only the stalks, no cap; ya I got screwed over, but I felt REALLY happy and up-ity, along with an intensified hyperness. Im pretty sure a good dose for begginers would be about an 1/8th. There really isnt that big of a chance of having a bad trip. Just make sure that the day that you do do them that you are not having a really bad day, that is pretty much what triggers a bad trip, or if you mix it with other drugs such as Meth. Stay in a room where you wont think you are too 'enclosed/surrounded'. Having a buddy trip with you, or be with you is the best thing though, they will keep you in check and will make the experience funner.