Effects are (at least for me) pretty subtle, i'd describe it as a mild relaxed feeling, but not tired at all.
As Venrak said 6-8g should be a good dose, if you go higher than that you might experience nausea.
In case you've got the crushed leaves and decide to make a tea be sure to chew on them a bit and swallow them afterwards, the chewing always seemed to enhance the effects for me.