Yes, I often use Ravelry. I also use knittingfool.com which lets you search stitch patterns by the number of stitches wide and also by the number of rows to complete. You can also look at them by content: such as you are looking for leaves, or a different way to make bobbles. Or you are working on squares and your square isn't wide enough so you can find a cable which is similar but has more stitches.
What I find is that I use free patterns as much as possible. But even when you pay for a pattern, you may not be fond of one of the elements. So it is a great tool from being able to make substitutions. Some of the patterns are charted, and then have written instructions, but most just have written instructions and a picture.
It isn't a place for getting a pattern for a cardigan, but if you have a cardigan you've knit and you want different cables on it, it will give your tried and true pattern a complete face lift. That way you KNOW your knitting will fit, so long as you are using the same brand of yarn, size of needles and didn't change your knitting style.