How Can I Prevent DDOS Attacks On My Site ?

You probably can't until it happens, try being nice to everyone then nobody will want to DDOS you.If they have/do then talk to your ISP/hosting admins and ask them to block the IP's that are sending to you - if they aren't spoofed that is.

try this I hope it helps youhttp://www.toplayer.com/content/resource/solutions/DoS.jsp?src=overture

Use linux, and Colp FYI. Attacks don't usually target individuals, they look for insecure systems, like windows. I have linux servers and they fend off thousands of ddos attacks every day.