If you could give the exact model number like dimension 9300, I could tell you exactly what your options are. Or you could open up the case and look at the existing hard drive and the motherboard's connectors. I attached a picture so that you can see the difference between serial ata and ide drives. Ide is the blue on the left and sata is the red on the right.
Once you figure out what connector you can use, make sure there is an available spot on the cable if it is ide, or make sure there is an available connector on the motherboard if it is sata. You can choose any brand hard drive, so long as it has the correct interface.
Ok. I looked up your computer and it shows me that you can only have sata drives, and a max of 4 of them (which is pretty nice). You could go ahead and purchase any sata drive of any manufacturer and it will work with your computer. Just remember that after you stick it in your computer, you need to format it either with the cd that comes with it or with windows before it is recoginzed by windows.
Just for reference i attached a schematic of the motherboard layout that i found.
Awesome choice of drive it is very nice. The only think i have to warn you of is since it says its oem it means you will only get the drive in a static bag. No cd, no sata cable. This shouldn't be a problem if you have an extra sata cable lying around, but if you don't i suggest you get the "retail" version of this drive for the few dollars more. It will come in the box like you would pick up at the store with instructions cables and the like.
Actually while looking at the site it unfortunatly doesnt appear that newegg sells any retail versions of hard drives anymore (maybe it costs to much to store). So just make sure you pick up a sata 2 cable at the purchase, and make sure dell left you with a slot to screw it into inside the case (should be right next to your existing drive).
Well I ended up getting the OEM one because of the price, and because I have a SATA cable to spare, but do I need software so my computer recognizes the drive or is it sort of a plug and play type thing (like it prompts me when I start up windows that there is a new drive and give me options for what to do with it?).
Thanks a lot!