If you look on the label on the wool there will be information which will tell you what size needles you need. I am knitting a scarf at the moment, using Kaffe Fawcett wool. It is fairly thick and I am using 7.00 mm needles.
If you also look on the label there will be a little tension square diagram. This will tell you how many stitches and rows you need to knit to produce this. I would recommend you do this. If you are a tight knitter you may need to switch to a larger size of needles and if you are a loose knitter you may need a smaller pair of needles. This will help you decide on the width of your scarf. I wanted a narrowish scarf which would be long. I have 35 stitches on the needle and my scarf measures 10 inches across. I am knitting in plain stitch and have bought 3 balls of wool 100g each. The first ball knitted 28 inches of scarf. I am going to put some tassels on the ends too, so I estimate the final length (excluding tassels) will be about 78 inches. I want to be able to wrap around my neck several times.
I knit between posts while I am waiting for the forum to reload.
Good luck Foxie
-------------------- I've learnt that people will forget what you said, people will forget what you did, but people will never forget how you made them feel. Maya Angelou.