Don't know how to attach a screw on to my corded Skil 3/s drill.
Is there a special bit for this purpose?
Welcome to fixya!
Yes, you need to use a bit with all drills. They come in different sizes and shapes. If you don't have any bits to put into your drill, an all purpose kit would be nice to have. You can find them at your local hardware store or online.
Check out this webpage: http://www.toolup.com/dewalt_dw2163_37-piece-screwdriving-set-with-tough-case.aspx
Copy and paste this entire web address into your browser and a page with one of the kits on it will open up for you. You don't have to buy a kit with lots of bits, you can pick up just one or two bits that you would use the most at the hardware store. The most used bits would be the #1 and #2 Phillips bits and a couple of different sizes of flat bladed bits. A few drill bits might come in handy too.
The drill that you have has a keyless chuck. This means you don't need any special tools to put in a bit or change one. If you look at the chuck, you'll see that the ridged part has two sections. If you hold the back section with your left hand, you can turn the front section to either open the chuck or close it to put bits in.
I don't know if this was clear or not, but if you have any problems or more questions about this, please be sure to reply back. I'll be glad to help you.