Piano sheet music is not difficult to TAB. If you know where the note was on a guitar, you can tab it. The only problem is, there are some of the same notes in the same octave playable twice on the guitar. You have to figure out what fingering is more comfortable or convenient for you. For example: there are two ways to play a middle "C" on guitar, 6th string 8th fret, and 5th string 3rd fret. "A" is 6th string 3rd fret, and 5th string open.
You can use guitar pro to convert the standard sheet music into guitar tabs,this way you can learn more about transcribing standard sheet music, into guitar tabs.