If you want sound you have to buy a sound card. A 16-bit sound card is usually sufficient. In this case you can buy an ISA or PCI interface sound card. If you want to get Internet access you have to buy a modem (modulator demodulator). A modem is what takes analog signals and converts them into digital signals for the computer to read. The standard today is a PCI 56 kilobit per second version 90 modem. Since we use the Internet a lot we bought one of those too. Another necessity is a CD ROM drive. Using a laser, the drive reads indentions in a coated piece of plastic to get information from it. A floppy drive is also needed to read information from disks. There is only one common type of floppy drive. That is usually a 1.44 megabyte 3.5 inch drive. One of the other pieces of hardware you need is a hard drive. That is where all of your information is stored so you can gain access to it at a later time. The very last thing you need is a monitor. The most common size is a 15- that can handle a 1024x768 display. After the salesman adds up all of the prices get ready to catch whoever's paying so they don't fall. Computers tend to be expensive so don't be shocked.
After I get home I like to build it and get it done to make sure everything works and I don't have to take it back. I usually get so carried away when I build a computer. It's like Christmas time for me. Boxes are spread all about the room, plastic wrap covers the floor and I'm having fun. The best thing you can do is make a nice workspace. Preferably a table where you can lay components out and not worry about them falling on the floor. I start by carefully unwrapping each one and lay it on the wrap it came in. Next I take the case and lay it out so it's accessible. I then plug the power cord into the surge protector so I have a good ground. Next consult the documentation and configure my motherboard for a 1.3 volt CPU and tell it how much RAM I have by setting jumpers on the board itself.