2 HDD -SATA & IDE-How to set them up

I am upgrading my computer. I am taking a GA945gcmx with Intel E2160.
I already have Windows XP on my 40 GB IDE HDD along with some important files.
As such when i upgrade, I will load the OS again on the new 250 GB Seagate SATA HDD as my primary drive.

I wanted you to advice me the best way to fix the 2 drives.

Should I put only the new drive in the system and complete the OS installation and after that is complete, add the 2nd old HDD ?
Will there be any compatibility problem in recognising the old HDD as it is IDE. As i am a novice, i wanted to know the easiest and safest method to install the 2 drives so that i have to do the minimum of tweaking and both work to full capacity without impairing the speed of SATA drive

Thanks

if you have important data on the old drive, to be safe don't install it until after you have windows setup on your new drive.
As for installing the old drive set the jumper on the ata drive to slave if you have an ata optical drive and install it on the middle ide connector.
Don't worry about the drive slowing down as motherboards nowadays don't have the slow down problem like they did 10 years ago.