Make 5 chain and join up into circle. Crochet 2chain then using the circle make 11 trebles using the middle of the circle. when complete make two chain stitches, then work three trebles into the first three trebles of row before, then two chain, then three more trebles into the same space - this, of course makes the corner.
Do the same with the next three, then the next until you have completed a square, finish off into first stitch of the first corner, then two chain up to start the next round. Carry on from then on and I'm sure you will be OK from then on. Just study a picture if you can of a granny square already made up. Plenty of advice shown in crocheting on net including one of the samples of a bedspread on thrifty fun site by a lady from Arkansas, USA. I have made several blankets with same coloured border to each square and then sewed them up together, or you could crochet same.