One option is to add karaoke components to your home stereo. It's quite simple to incorporate a karaoke CDG player into a stereo system. Actually it's very similar to putting in a typical DVD player. A karaoke player features microphone receptacles along with adjustments which may cause you to think that the only thing you need to do is connect a microphone to be ready to sing. It isn't that simplistic and there will be issues to think about first.
The primary issue will concern the speaker system. Live karaoke vocals are very different than the recorded music that you usually play and common stereo speakers, although they may be of heavy duty design, are not going to provide very good sound. There is also a possibility of damaging or destroying the speakers. Needless to say, surround sound system speakers should never be used. You will want to acquire a couple of PA speakers for use when undertaking karaoke. There are many models available to fit in various decors.
More than likely your stereo's amplifier or receiver/amp has enough power to effectively implement karaoke. Understanding the power output rating of the amplifier will permit you to properly coordinate the appropriate PA speakers for your sound system. As a rule of thumb the amplifier should have a maximum power output that is double the combines RMS power handling of the speakers.
For home use, wired microphones should be sufficient. Wireless models of similar quality will cost considerably more. You will find a decent quality wired microphones for less than $100 in most sound gear stores. AKG and Shure are two of the superior brands to keep in mind.
The karaoke songs will be found on CDG discs. This remains the most accepted karaoke song type and boasts significantly more songs than every other format combined. CDG discs are generally sold at most music shops and the music section of department stores. The most comprehensive selection will be located at online stores and the manufacturer's websites. You may be able to locate some used discs at auction sites like eBay.
Should you desire that your karaoke system be east to transport then an all-in-one unit may be the more viable option. These systems vary from smaller boom-box type units to much larger multiple speaker models powerful enough to handle a good sized room. They're ideal taking outdoors on a patio or perhaps to someone's party. Many of the boom-box style units have an integrated monitor for displaying the lyrics. Other larger models need to be hooked up to a TV or monitor.
For the ultimate experience you could always choose to put together a professional karaoke system that incorporates an amplifier, mixer (or powered mixer), and PA speakers, that would offer you a lot more sound control.