Bear's nails were very long when we adopted him. I started clipping them, just a tiny bit, every 4-5 days. I've always be so scared of cutting the quick because he has dark nails. They're slowly getting better, over the past month and a half. I also use an emery board/buffer combo when he's sleeping in my lap on the sofa. It doesn't bother him, but it smooths out the rough edges from clipping.
I've heard of people here using a dremel, but when I turn it on for them to get used to the sound of it, they run for their kennels. I did a google search and found, what I thought, is a very good tutorial for using the dremel.
http://homepages.udayton.edu/~merensjp/ ... remel.html
There are no videos, I'm sure a youtube search would give some, but the pictures on the site are good and there's lots of information, including how to get them used to it.
Hardwood floors are expensive to replace, but scratches aren't a big deal. We had hardwood floors when I was a kid. We used to rollerblade through the house. It used to make my mother so mad, but my father would buff out the scratches with low grit sand paper and then lay on a layer of wax and buff it in with an electric car buffer.