Drives

Hard Drive

Modern hard drives will use a SATA communication interface to communicate with the computer (left below), so make sure you don't accidentally get an outdated IDE hard drive (right below). There are basically only two important things to consider when purchasing a hard drive. Capacity, and rotational speed (RPM). Capacity is merely a personal preference anymore. It's all about how much stuff you're going to store. Hard drives are rated in gigabytes, which is a measurement of storage space. One gigabyte is approximately enough space to store 1,000 8 megapixel photos or about 100 good quality songs. Hard drives are another very easy to upgrade item because most motherboards can support several hard drives. So, if you start running out of storage space then you can just add another hard drive. As for RPM, the faster the better. The standard for desktop hard drives is 7200 RPM. RPM lower than 7200 probably won't save you much money but will sacrifice a lot of performance. Anything higher performance than that is usually not needed for most applications, although can be nice if you've got the money to blow. It usually makes things load a bit faster and you might notice a slight performance increase in really high performance games.

CD Drive

Purchasing a CD drive is a simple but essential step. If you plan on installing an operating system on your new computer with a CD then it is a must have. Most CD drives will connect through SATA just like hard drives, although there are still some IDE based hard drives so watch out for that. Purchasing a CD drive is really just a matter of what kind of features you would like. Do you need to burn DVDs? Make sure it can. Other than that, pick a well reviewed item things should go smoothly.