Preliminary research very quickly indicated that a granny square should definitely NOT be your very first foray into crochet! Here's why (according to me): it is very difficult to judge which are the chain spaces to work in, until you've had some practice.
As an illustration, I'm reproducing below the photo of my initial granny square swatch, which I had to make owing to the rules of the Harry Potter Rav group. Try counting the clusters in each round (if you can!). You'll see I totally failed to produce even rounds:
On my next attempt, which was after I'd had thoroughly practised clusters, including some into chain spaces (see previous blog entry Plaited Scarf) I discovered that using different coloured yarn can help to maintain even rounds:
|Traditional granny square|
And if you make two 9-in squares, one 6-in mandala, and a length of granny stripe, and crochet the pieces together, you end up with a bag that looks like this:
Instructions for making this bag can be found on Ravelry (note: Rav log-in may be required). To make mine, I used a 4mm hook and ggh Tavira aran yarn in plum, pale pink, white and burgundy.