Knitting Help has been a great HELP to me!! I love the videos! I started knitting hats and since then learned to knit sweaters. I LOVE this hobby and look forward to talking and meeting other "knit wits"
There's no way to directly convert grams to yards because each weight (thickness) of yarn will vary from another. 50 grams can be 80 yards in chunky, 100-120 in worsted, 150 in DK or 200 in laceweight. So it depends on the yarn. You can find all kinds of yarns by gauge at yarndex.com, the descriptions may help you figure it out.
There are no silly questions! You can also buy a yarn meter, if you're really interested (see http://www.knittersreview.com/articl...e/050818_c.asp for more information). I generally do what Sue does and check yarndex. OR, just use your mystery yarn for a project where the exact length doesn't really matter (like a scarf, which can be short or long) or a bunch of small pieces (like hats and mittens).