cumming, if u have a mic (the kind used for voice chatting), download and install free tuner software from http://www.aptuner.com/cgi-bin/aptuner/apmain.htmlOriginally Posted by cumming soon
It will show you the note as u play a string. u can place the mic near the guitar and play to get the guitar tuned. You need not buy cable for just tuning. But cable is good if you want to record guitar through line-input of soundcard. Such recording can mask all external noises.
You have to tune by ears using online tuners (the ones that provide notes of tuned strings). The tuner software i mentioned above picks sound through mic and determines and displays the note and can guide you until it is tuned to high precision. Moreover you can use it to a multitude of other uses like quickly learning notes and octaves on frets which u can't do with online tuners