I'm building a computer, and am looking at the Intel dx48bt2 mothboard. My questions are:

1: It says it supports DDR3 Ram- does that mean it ONLY supports DDR3 or is DDR2 still able to work as well?
2: How do I know what type of hard drive is compatible? I'm looking at a Seagate Barricuda 500gb SATA HD, but want to make sure its compatible before I spend any many.

Thanks in advance ;]