I thought I'd put the pattern I'm using for the Granny Squares on here. If anybody is struggling/yet to learn, I hope it will help them - I've found it far and away the easiest to follow. I'm going to copy it word for word from The Crochet Answer Book by Edie Eckman, which I think is an American book, meaning some of the stitches may be called different things than they are in the UK (just to keep us on our toes!) - so I shall reproduce the explanations of the stitches too. Here goes:
1 Yarn round hook
2 Pull yarn through stitch on hook
1 Insert hook into next stitch
2 Yarn round hook
3 Pull yarn through both loops on hook
Double crochet stitch:
1 Yarn round hook
2 Insert hook into next stitch (or into the space below the stitch for Granny Squares)
3 Pull yarn through stitch (3 loops on hook)
4 Yarn round hook
5 Pull yarn through 2 hoops on hook
6 Repeat steps 4 and 5.
GRANNY SQUARE PATTERN
MC = Main colour
CC = Contrasting colour
dc = double crochet
ch = chain
With MC, ch 4, join with a slip stitch to form ring.
Round One: Ch 3 (counts as dc), 2 dc in ring, *ch 1, 3 dc in ring; repeat from *two more times, ch 1, join to top of ch-3 with a slip stitch. Cut off MC and end off.
Round Two: Attach CC in any chain space. (Ch 3, 2 dc, ch1, 3 dc, ch1) in chain space, *(3 dc, ch1, 3dc, ch1) in next chain space; repeat from *two more times, join to top of ch-3. Cut CC and end off.
Round Three: Attach MC to any space between groups. (Ch 3, 2 dc, ch1) in chain space, *(3 dc, ch1, 3 dc) in next chain space, ch 1; 3 dc in next space, ch 1, repeat from *two more times, (3 dc, ch 1, 3 dc) in next space, ch 1, join with slip stitch. Break MC.
See how you are increasing 3 stitches in each of the four corners, with groups of 3 dc in each chain space? With each additional round, you continue to work increased in the corners separated by groups of 3 dc in between. You can continue doing this ad infinitum.
That's how it's laid out in the book. I find, as long as you remember you have to do a chain stitch after every 3 dc, and that you need two groups of 3 dc in each corner, you can't go wrong.
I hope that's a help. If anyone still has any problems I'll try and help, but I'm only a beginner myself so might not be able to! lol. :)