Hi ipackrat21, that little green led you see is telling you the motherboard has standby power. (Its supposed to be green & on).
Make sure the hdd jumper is set to, master without a slave). In a one hdd system.
When you replaced the hdd you also need to enter the bios menu.
In the bios you'll need to make some changes. First you should see the new hdd listed in the bios. (Normally it list the hdd by model). If your hdd is shown than go to the title "BOOT". You need to set the boot order. A normal boot order would list like so;
First boot device, Floppy disk drive".
Second boot device, "CR-ROM" drive.
Third boot device, "Your new hdd".
If your bios does not see your hdd you'll need to re-check the data cable from the board to the drive. (Make sure it is fully connected).
If the drive is an IDE/PATA make sure it has power. A 4-pin molex.
Good luck ipackrat21!
Still have trouble, post it here.