There are many felting needles available and it can be confusing as to which will be useful for your projects. Please see my needle guide for the current felting needles available from Heidifeathers.com . Some people find a needle felting kit a good starting point, our felting kit include all the felting supplies you need.
If you are a beginner to needle felting I would suggest a mixed pack of needles to learn what each can do. Once you get the hang of things its then worth experimenting with a few other needles such as the star needles, reverse needle and the new twisted needles.